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Web Engineering:
Principles and Techniques
WoojongSuh
InhaUniversity,Korea
Hershey • London • Melbourne • Singapore
IDEA GROUP PUBLISHING

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Library of Congress Cataloging-in-Publication Data
Web engineering : principles and techniques / Woojong Suh, editor.
p. cm.
Includes bibliographical references and index.
ISBN 1-59140-432-0 (hard cover) -- ISBN 1-59140-433-9 (soft cover) -- ISBN
1-59140-434-7 (Ebook)
1. Web site design. 2. Web servers. 3. Application software--Development. I.
Suh,Woojong.
TK5105.888.W3727 2004
006.7--dc22
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All work contributed to this book is new, previously-unpublished material. The views expressed in
this book are those of the authors, but not necessarily of the publisher.

Web Engineering:
Principles and Techniques
Table of Contents
Preface .......................................................................................................................... vi
SECTION I: WEB ENGINEERING: CONCEPTS AND REFERENCE MODEL
ChapterI.
WebEngineering:IntroductionandPerspectives .........................................................1
San Murugesan, Southern Cross University, Australia
Athula Ginige, University of Western Sydney, Australia
ChapterII.
WebEngineeringResourcesPortal(WEP):AReferenceModelandGuide ............. 31
Sotiris P. Christodoulou, University of Patras, Greece
Theodore S. Papatheodorou, University of Patras, Greece
SECTION II:WEB APPLICATION DEVELOPMENT:METHODOLOGIES AND TECHNIQUES
ChapterIII.
WebApplicationDevelopmentMethodologies ............................................................ 76
Jim Q. Chen, St. Cloud State University, USA
Richard D. Heath, St. Cloud State University, USA
ChapterIV.
RelationshipAnalysis:ATechniquetoEnhanceSystemsAnalysisforWeb
Development ................................................................................................................ 97
Joseph Catanio, LaSalle University, USA
Michael Bieber, New Jersey Institute of Technology, USA

ChapterV.
EngineeringLocation-BasedServicesintheWeb ................................................... 114
Silvia Gordillo, LIFIA, UNLP, Argentina
Javier Bazzocco, LIFIA, UNLP, Argentina
Gustavo Rossi, LIFIA, UNLP, Argentina, and Conicet, Argentina
Robert Laurini, LIRIS, INSA-LYON, France
SECTION III:WEB METRICS AND QUALITY:MODELS AND METHODS
ChapterVI.
ArchitecturalMetricsforE-Commerce:ABalancebetweenRigorand
Relevance................................................................................................................... 132
Jinwoo Kim, Yonsei University, Korea
ChapterVII.
TheeQualApproachtotheAssessmentofE-CommerceQuality:ALongitudinal
StudyofInternetBookstores .................................................................................... 161
Stuart J. Barnes, Victoria University of Wellington, New Zealand
Richard Vidgen, University of Bath, UK
ChapterVIII.
WebCostEstimation:AnIntroduction ..................................................................... 182
Emilia Mendes, University of Auckland, New Zealand
Nile Mosley, MetriQ (NZ) Limited, New Zealand
SECTION IV: WEB RESOURCE MANAGEMENT: MODELS AND TECHNIQUES
ChapterIX.
Ontology-SupportedWebContentManagement ...................................................... 203
Geun-Sik Jo, Inha University, Korea
Jason J. Jung, Inha University, Korea
ChapterX.
DesignPrinciplesandApplicationsofXRML.......................................................... 224
Jae Kyu Lee, Korea Advanced Institute of Science and Technology, Korea
Mye M. Sohn, Sungkyunkwan University, Korea
SECTION V: WEB MAINTENANCE AND EVOLUTION: TECHNIQUES AND METHODOLOGIES
ChapterXI.
ProgramTransformationsforWebApplicationRestructuring .............................. 242
Filippo Ricca, ITC-irst, Italy
Paolo Tonella, ITC-irst, Italy

ChapterXII.
TheRequirementsofMethodologiesforDevelopingWebApplications .................. 261
Craig Standing, Edith Cowan University, Australia
ChapterXIII.
ACustomerAnalysis-BasedMethodologyforImprovingWebBusiness
Systems ..................................................................................................................... 281
Choongseok Lee, Samsung SDS Co., Korea
Woojong Suh, Inha University, Korea
Heeseok Lee, Korea Advanced Institute of Science and Technology, Korea
SECTION VI: WEB INTELLIGENCE: TECHNIQUES AND APPLICATIONS
ChapterXIV.
AnalysisandCustomizationofWeb-BasedElectronicCatalogs ............................. 309
Benjamin P.-C. Yen, The University of Hong Kong, China
ChapterXV.
DataMiningUsingQualitativeInformationontheWeb .......................................... 332
Taeho Hong, Pusan National University, Korea
Woojong Suh, Inha University, Korea
AbouttheAuthors ..................................................................................................... 353
Index ........................................................................................................................ 360

vi
Preface
About this Book
Since the advent of the Web, every aspect of our lives and organizational activities has
changed dramatically. Organizations’ expectations and dependencies on the use of
Web technologies have increased rapidly over the years. Most organizations have
conceived these Web technologies as a critical instrument for enhancing their perfor-
mance; they have made every effort to develop, use, and maintain Web-based applica-
tions successfully. Nevertheless, such efforts are faced with various complexity and
diversity caused by the demands for not only developing large-scale systems but also
extending their applications into various domains. In most cases, these challenges are
handled in an ad hoc manner rather than systematically. This phenomenon is a result of
the fact that the progress of development and maintenance processes of Web applica-
tions have not kept up sufficiently with the rapid expansion of the challenges.
As a new approach to solve such challenges, Web Engineering has recently drawn
great attention. Web Engineering is a multidisciplinary field encompassing diverse
principles primarily based on management information systems and computer science.
Its major specific areas include systems analysis and design, software engineering,
hypermedia engineering, human-computer interaction, requirement engineering, data
mining, project management, artificial intelligence, and Web programming. Web Engi-
neering has the purpose of effectively supporting the organizational activities con-
cerned with the lifecycle of Web applications or Web projects. Such activities include
the following issues primarily: development and maintenance process, quality assess-
ment, Web intelligence, Web resource management, and Web project management.
These issues are often dealt with in terms of methodology, process, model, technique,
or technology.

vii
For the past few years, the researchers’ interests in Web Engineering have significantly
increased; an international conference on Web Engineering has been held since 2001,
and the first journal on Web Engineering, Journal of Web Engineering, was published
in 2002. Nevertheless, the concept or perspective of Web Engineering does not seem to
have been introduced widespread yet; now it is the early stage of Web Engineering.
This is the fundamental motivation for publishing this book.
This book aims to enhance the professional insights and capabilities of researchers
and technical professionals. Hence, it places emphasis on serving both theoretical
understanding and the latest research results in the major sub-areas of Web Engineer-
ing. It is expected that this book will be used as a useful educational textbook for
classes in graduate schools, as well as helpful material for current and future research
by researchers in universities and research institutions. In addition, it will serve a
variety of technologies, methodologies, and techniques to help Web projects from
practical perspectives, so it also is expected to help Web professionals in various
industries improve their business capabilities.
This book is organized into six sections: Web Engineering: Concepts and Reference
Model; Web Application Development: Methodologies and Techniques; Web Metrics
and Quality: Models and Methods; Web Resource Management: Models and Tech-
niques; Web Maintenance and Evolution: Techniques and Methodologies; and Web
Intelligence: Techniques and Applications.
Section I: Web Engineering: Concepts and Reference Model
The two chapters in this section are designed to provide readers with the introduction
to Web Engineering and a reference model for the Web engineers. Chapter 1, Web
Engineering: Introduction and Perspectives, raises the issues and considerations in
large, complex Web application development, and introduces Web Engineering as a
way of managing complexity and diversity of large-scale Web development. Chapter 2,
Web Engineering Resources Portal (WEP): A Reference Model and Guide, provides
the Web Engineering Resources Portal (WEP) as a basic reference model and guide, to
serve several cross-referenced taxonomies of technologies, research results, and tools
for the Web engineers.
Section II: Web Application Development: Methodologies and Techniques
This section includes three chapters related to the development of Web applications.
Chapter 3, Web Application Development Methodologies, discusses the challenges in
relation to Web application development and proposes a Modified Prototyping Method
(MPM) for developing the system. Chapter 4, Relationship Analysis: A Technique to
Enhance Systems Analysis for Web Development, presents a comprehensive, system-
atic, domain-independent analysis technique, Relationship Analysis (RA), which can
help the design of the navigational links in developing Web applications. Chapter 5,
Engineering Location-Based Services in the Web, discusses the state of the art of
location-based services and presents an object-oriented design approach for engineer-
ing location-based applications that effectively supports the evolution of these appli-
cations.

viii
Section III: Web Metrics and Quality: Models and Methods
The three chapters in this section focus on the measurement concerning Web busi-
ness, Web applications, and Web projects. Chapter 6, Architectural Metrics for E-
Commerce: A Balance between Rigor and Relevance, proposes six dimensions of
architectural metrics for Internet businesses and reports the results of large-scale em-
pirical studies to validate the proposed metrics and to explore their relevance across
four Internet business domains. Chapter 7, The eQual Approach to the Assessment of
E-Commerce Quality: A Longitudinal Study of Internet Bookstores, introduces eQual,
an instrument for assessing the quality for Web sites, and examines online bookshops,
one based on eQual 2.0 and the other on eQual 4.0, to evaluate the use of the instrument
and the benchmarking of the bookshops on two separate occasions. Chapter 8, Web
Cost Estimation: An Introduction, introduces a literature review of Web cost estima-
tion, then compares the literature according to set criteria, and discusses Web size
measures.
Section IV: Web Resource Management: Models and Techniques
The two chapters in this section propose applications of theoretical models and tech-
niques to manage and use Web resources. Chapter 9, Ontology-Supported Web Con-
tent Management, describes how to exploit ontology to manage Web contents and
resources and introduces case studies on personalization from user-specific content
and a comparison-shopping mall system in electronic commerce. Chapter 10, Design
Principles and Applications of XRML, proposes a language eXtensible Rule Markup
Language (XRML) which is an emerging architecture to share Web resources be-
tween human and software agents, and identifies its potential application areas and
challenges.
Section V: Web Maintenance and Evolution: Techniques and Methodologies
The three chapters included in this section focus on the maintenance and evolution of
Web applications. Chapter 11, Program Transformations for Web Application Restruc-
turing, discusses the role of restructuring Web applications in a highly dynamic and
rapidly evolving development environment, and examines specific examples in several
different contexts to investigate the possibility to automate restructuring. Chapter 12,
The Requirements of Methodologies for Developing Web Applications, identifies the
main requirements of methodologies for developing e-commerce applications, and in-
troduces Internet Commerce Development Methodology (ICDM) which considers evo-
lutionary development of systems. Chapter 13, A Customer Analysis-Based Methodol-
ogy for Improving Web Business Systems, discusses the challenges in the development
of Web business systems, explores the previous methodologies by comparing them,
and proposes a Customer Analysis-based Improvement Methodology (CAIM) to help
evolve customer-oriented Web business systems, employing scenario-based and ob-
ject-oriented approaches.
Section VI: Web Intelligence: Techniques and Applications
The two chapters included in this section deal with various techniques and applica-
tions related to Web intelligence. Chapter 14, Analysis and Customization of Web-

ix
Based Electronic Catalogs, presents a Personalized Electronic Catalog (PEC) system
to synthesize the Web-based electronic catalog customization on information content,
organization and display for electronic catalogs, and applies the system to electronic
catalogs in an industrial application to demonstrate the analysis and improvement of
information access. Chapter 15, Data Mining Using Qualitative Information on the
Web, proposes a Web mining application, KBNMiner (Knowledge-Based News Miner),
to predict interest rates by employing qualitative information on the Web, and makes an
experiment by the use of Web news information to validate the effectiveness of the
KBNMiner.
Woojong Suh
Inha University, Korea
December 2004

x
Acknowledgments
This book could not come into the world without great help from numerous individuals
who contributed. First of all, I would like to thank all of the authors for their insights
and excellent contributions. They accepted my comments and suggestions for the
scope of chapter themes, the balances in the chapter structure, and other requirements
for accomplishing the goal of the book. I am sure that such cooperation was the most
critical factor in publishing the book successfully.
Web engineering is an emerging area, so establishing its scope and identifying practi-
cal needs are important in creating value in this book. I could confirm my decision on
these points through professional opinions by San Murugesan of Southern Cross
University and Heeseok Lee of Korea Advanced Institute of Science and Technology
from the academic standpoint and by Dr. Choongseok Lee of Samsung SDS Co. and Dr.
Jaewoo Jung of IBM BCS Korea from the practical standpoint. I wish to give special
thanks to all of them. Also I would especially like to thank San Murugesan, General
Chair of International Conference on Web Engineering(ICWE) 2005, who gave an op-
portunity to introduce the book to ICWE 2004 in Munich.
In addition, I wish to thank all the people who helped me throughout the process of the
publishing project. I am very grateful to everyone who assisted me in the reviewing
process, including Gyoogun Lim of Sejong Univiersity, Kyoungjae Kim of Dongguk
University, Changhee Han of Hanyang University, Hwagyoo Park, Kyungdong Univer-
sity, and Taeho Hong of Pusan University. Special thanks also goes to the publishing
team at Idea Group, Inc. In particular, Dr. Mehdi Khosrow-Pour invited me to take an
opportunity to work with IGP, and Jan Travers, Amanda Appicello, Michele Rossi,
Jennifer Sundstrom, and Amanda Phillips provided me with ongoing professional sup-
port throughout this project. Their enthusiasm was strong enough for the book to be
published successfully. Finally, I want to thank my wife for her love and support during
this project.
Woojong Suh
Inha University, Korea
December 2004

Section I
Web Engineering:
Concepts and Reference Model

Web Engineering 1
Copyright © 2005, Idea Group Inc. Copying or distributing in print or electronic forms without written
permission of Idea Group Inc. is prohibited.
Chapter I
WebEngineering:
Introduction and
Perspectives
Abstract
Web-based systems and applications now deliver a complex array of functionality to
a large number of diverse groups of users. As our dependence and reliance on the Web
has increased dramatically over the years, their performance, reliability and quality
have become paramount importance. As a result, the development of Web applications
has become more complex and challenging than most of us think. In many ways, it is
also different and more complex than traditional software development. But, currently,
the development and maintenance of most Web applications is chaotic and far from
satisfactory. To successfully build and maintain large, complex Web-based systems and
applications, Web developers need to adopt a disciplined development process and a
sound methodology. The emerging discipline of Web engineering advocates a holistic,
disciplined approach to successful Web development. In this chapter, we articulate and
raise awareness of the issues and considerations in large, complex Web application
development, and introduce Web engineering as a way of managing complexity and
diversity of large-scale Web development.
San Murugesan
Southern Cross University, Australia
Athula Ginige
University of Western Sydney, Australia

2 Murugesan and Ginige
Introduction
Within a decade, the World Wide Web has become ubiquitous, and it continues to grow
unabated at exponential rate. Web-based systems and applications now deliver a
complex array of varied content and functionality to a large number of heterogeneous
users. The interaction between a Web system and its backend information systems has
also become more tight and complex.
As we now increasingly depend on Web-based systems and applications, their perfor-
mance, reliability and quality have become paramount importance, and the expectations
of and demands placed on Web applications have increased significantly over the years.
As a result, the design, development, deployment and maintenance of Web-based
systems have become more complex and difficult to manage.
Though massive amounts of Web development and maintenance continue to take place,
most of them are carried out in ad hoc manner, resulting in poor quality Web systems and
applications. Problems such as outdated or irrelevant information, difficulties in using
the Web site and finding relevant information of interest, slow response, Web site
crashes, and security breaches are common. We encounter these kinds of problems
because Web developers failed to address users’ needs and issues such as content
management, maintenance, performance, security, and scalability of Web applications.
They also often overlook important non-technical considerations such as copyright and
privacy.
Many Web developers seem to think that Web application development is just simple
Web page creation using HTML or Web development software such as Front Page or
Dreamweaver and embodying few images and hyperlinking documents and Web pages.
Though certain simple applications such as personal Web pages, seminar announce-
ments, and simple online company brochures that call for simple content presentation
and navigation fall into this category, many Web applications are complex and are
required to meet an array of challenging requirements which change and evolve. There
is more to Web application development than visual design and user interface. It involves
planning, Web architecture and system design, testing, quality assurance and perfor-
mance evaluation, and continual update and maintenance of the systems as the require-
ments and usage grow and develop.
Hence, ad hoc development is not appropriate for large, complex Web systems, and it
could result in serious problems: the delivered systems are not what the user wants; they
are not maintainable and scalable, and hence have short useful life; they often do not
provide desired levels of performance and security; and/or most Web systems are often
much behind schedule and overrun the budget estimates.
More importantly, many enterprises and organisations cannot afford to have faulty Web
systems or tolerate downtime or inconsistent or stale content/information. The problems
on the Web become quickly visible and frustrate the users, possibly costing the
enterprises heavily in terms of financial loss, lost customer and loss of reputation. As
is often said, “We cannot hide the problems on the Web.”
Unfortunately, despite being faced with these problems and challenges, most Web
application development still continues to be ad hoc, chaotic, failure-prone, and unsat-

Web Engineering 3
isfactory. And this could get worse as more inherently complex Web systems and
applications that involve interaction with many other systems or components pervade
us and our dependence on them increases.
To successfully build large-scale, complex Web-based systems and applications, Web
developers need to adopt a disciplined development process and a sound methodology,
use better development tools, and follow a set of good guidelines.
The emerging discipline of Web engineering addresses these needs and focuses on
successful development of Web-based systems and applications, while advocating a
holistic, disciplined approach to Web development.
Web Engineering uses scientific, engineering, and management principles and system-
atic approaches to successfully develop, deploy, and maintain high-quality Web
systems and applications (Murugesan et al., 1999). It aims to bring Web-based system
development under control, minimise risks and improve quality, maintainability, and
scalability of Web applications.
The essence of Web engineering is to successfully manage the diversity and complexity
of Web application development, and hence, avoid potential failures that could have
serious implications.
This chapter aims to articulate and raise awareness of the issues and considerations in
large-scale Web development and introduce Web engineering as a way of managing
complexity and diversity of large-scale Web development.
Following a brief outline of the evolution of the Web and the categorisation of Web
applications based on their functionality, this chapter examines current Web develop-
ment practices and their limitations, and emphasises the need for a holistic, disciplined
approach to Web development. It then presents an overview of Web engineering,
describes an evolutionary Web development process, discusses considerations in Web
design and recommends ten key steps for successful development. In conclusion, it
offers perspectives on Web Engineering and highlights some of the challenges facing
Web developers and Web engineering researchers.
Evolution of the Web
The Web has become closely ingrained with our life and work in just a few years. From
its initial objective of facilitating easy creation and sharing of information among a few
scientists using simple Web sites that consisted primarily of hyperlinked text documents,
the Web has grown very rapidly in its scope and extent of use, supported by constant
advances in Internet and Web technologies and standards. In 10 years, the number of
Web sites dramatically has grown from 100 to over 45 million (Figure 1).
Enterprises, travel and hospitality industries, banks, educational and training institu-
tions, entertainment businesses and governments use large-scale Web-based systems
and applications to improve, enhance and/or extend their operations. E-commerce has
become global and widespread. Traditional legacy information and database systems are
being progressively migrated to the Web. Modern Web applications run on distributed

Figure 1. Growth of Web sites
hardware and heterogeneous computer systems. Furthermore, fuelled by recent ad-
vances in wireless technologies and portable computing and communication devices, a
new wave of mobile Web applications are rapidly emerging. The Web has changed our
lives and work at every level, and this trend will continue for the foreseeable future.
The evolution of the Web has brought together some disparate disciplines such as media,
information science, and information and communication technology, facilitating easy
creation, maintenance, sharing, and use of different types of information from anywhere,
any time, and using a variety of devices such as desktop and notebook computers, pocket
PCs, personal digital assistants (PDAs), and mobile phones. Contributions of each of
these disciplines to the evolution and growth of the Web are:
• Media: integration of different types of media such as data, text, graphics, images,
audio and video, and their presentation (animation, 3D visualisation); different
types of interaction and channels of communications (one-to-one, one-to-many,
many-to-one, and many-to-many).
• Information science: information organisation, presentation, indexing, retrieval,
aggregation, and management; and collaborative and distributed content creation.
• Information and communication technology and networking:efficient and cost-
effective storage, retrieval, processing, and presentation of information; infra-
structures that facilitate transfer and sharing of data and information; wired and
wireless Internet communication; and personalised and context-aware Web appli-
cations.
Note: Web Sites = Number of Web servers; one host may have multiple sites by using different
domains or port numbers.
Source: Hobbes’ Internet Timeline, 2004, www.zakon.org/robert/internet/timeline/

Web Engineering 5
Many new Web technologies and standards have emerged in the last couple of years to
better support new, novel Web applications: XML, Web services, the Semantic Web,
Web personalisation techniques, Web mining, Web intelligence, and mobile and context-
aware services.
The advances in Internet and Web technologies and the benefits they offer have led to
an avalanche of Web sites, a diverse range of applications, and phenomenal growth in
the use of the Web.
Categories of Web Applications
The scope and complexity of Web applications vary widely: from small scale, short-lived
(a few weeks) applications to large-scale enterprise applications distributed across the
Internet, as well as via corporate intranets and extranets. Web applications now offer
vastly varied functionality and have different characteristics and requirements. Web
applications can be categorised in many ways — there is no unique or widely accepted
way. Categorisation of Web applications based on functionality (Table 1) is useful in
understanding their requirements and for developing and deploying Web-based sys-
tems and applications.
Web Development Practices
Web development has a very short history, compared to the development of software,
information systems, or other computer applications. But within a period of few years,
a large number of Web systems and applications have been developed and put into
widespread use.
Table 1. Categories of Web applications based on functionality
Functionality/Category Examples
Informational Online newspapers, product catalogues, newsletters,
manuals, reports, online classifieds, online books
Interactive Registration forms, customized information
presentation, online games
Transactional Online shopping (ordering goods and services), online
banking, online airline reservation, online payment of
bills
Workflow oriented Online planning and scheduling, inventory
management, status monitoring, supply chain
management
Collaborative work
environments
Distributed authoring systems, collaborative design
tools
Online communities,
marketplaces
Discussion groups, recommender systems, online
marketplaces, e-malls (electronic shopping malls),
online auctions, intermediaries

The complexity of Web-based applications has also grown significantly — from infor-
mation dissemination (consisting of simple text and images to image maps, forms,
common gateway interface [CGI], applets, scripts, and style sheets) to online transac-
tions, enterprise-wide planning and scheduling systems, Web-based collaborative work
environments, and now multilingual Web sites, Web services and mobile Web applica-
tions.
Nevertheless, many consider Web development primarily an authoring work (content/
page creation and presentation) rather than application development. They often get
carried away by the myth that “Web development is an art” that primarily deals with
“media manipulation and presentation.” Sure, like the process of designing and con-
structing buildings, Web development has an important artistic side. But Web develop-
ment also needs to follow a discipline and systematic process, rather than simply hacking
together a few Web pages.
Web applications are not just Web pages, as they may seem to a causal user. The
complexity of many Web-based systems is often deceptive and is not often recognised
by many stakeholders — clients who fund the development, Web development managers
and Web developers — early in the development.
Several attributes of quality Web-based systems such as usability, navigation, acces-
sibility, scalability, maintainability, compatibility and interoperability, and security and
reliability often are not given the due consideration they deserve during development.
Many Web applications also fail to address cultural or regional considerations, and
privacy, moral and legal obligations and requirements. Most Web systems also lack
proper testing, evaluation, and documentation.
While designing and developing a Web application, many developers fail to acknowl-
edge that Web systems’ requirements evolve, and they do not take this into consider-
ation while developing Web systems. Web-based systems development is not a one-time
event as perceived and practiced by many; it is a process with an iterative lifecycle.
Another problem is that most Web application development activities rely heavily on the
knowledge and experience of individual (or a small group of) developers and their
individual development practices rather than standard practices.
Anecdotal evidence and experience suggest that the problems of ad hoc development
(outlined above and in the Introduction section) continue to be faced by developers,
users, and other stakeholders. As a result, these are increasing concerns about the
manner in which complex Web-based systems are created as well as the level of
performance, quality, and integrity of these systems.
“Many organisations are heading toward a Web crisis in which they are
unable to keep the system updated and/or grow their system at the rate that
is needed. This crisis involves the proliferation of quickly ‘hacked together’
Web systems that are kept running via continual stream of patches or
upgrades developed without systematic approaches.” (Dart, 2000)
Poorly developed Web-based applications have a high probability of low performance
and/or failure. Recently, large Web-based systems have had an increasing number of

Web Engineering 7
failures (Williams, 2001). In certain classes of applications such as supply-chain
management, financial services, and digital marketplaces, a system failure can propagate
broad-based problems across many functions, causing a major Web disaster. The cost
of bad design, shabby development, poor performance, and/or lack of content manage-
ment for Web-based applications has many serious consequences.
The primary causes of these failures are a lack of vision, shortsighted goals, a flawed
design and development process, and poor management of development efforts — not
technology (Ginige & Murugesan, 2001a). The way we address these concerns is critical
to successful deployment and maintenance of Web applications.
Therefore, one might wonder whether development methodologies and processes
advocated over the years for software or information systems development and software
engineering principles and practices could be directly used for developing Web appli-
cations. Though the valuable experiences gained and some of processes and method-
ologies used in software engineering (and other domains) could be suitably adapted for
Web development as appropriate, they are not adequate, as Web development is rather
different from software development in several aspects.
Web Development is Different
It is important to realise that Web application development has certain characteristics
that make it different from traditional software, information system, or computer appli-
cation development (Deshpande et al., 2002; Deshpande & Hansen, 2001; Ginige &
Murugesan, 2001a, 2001b; Glass, 2001; Lowe 2003; Murugesan et al., 1999; Pressman,
2001and2004).
Web applications have the following characteristics:
• Web applications constantly evolve. In many cases, it is not possible to fully
specify what a Web site should or will contain at the start of the development
process, because its structure and functionality evolve over time, especially after
the system is put into use. Further, the information contained within and presented
by a Web site will also change. Unlike conventional software that goes through a
planned and discrete revision at specific times in its lifecycle, Web applications
continuously evolve in terms of their requirements and functionality (instability of
requirements). Managing the change and evolution of a Web application is a major
technical, organisational and management challenge — much more demanding
than a traditional software development.
• Further, Web applications are inherently different from software. The content,
which may include text, graphics, images, audio, and/or video, is integrated with
procedural processing. Also, the way in which the content is presented and
organised has implications on the performance and response time of the system.
• Web applications are meant to be used by a vast, variable user community — a large
number of anonymous users (could be many millions like in the cases of eBay and
the 2000 Sydney Olympics Web site) with varying requirements, expectations, and

skill sets. Therefore, the user interface and usability features have to meet the needs
of a diverse, anonymous user community to whom we cannot offer training
sessions, thus complicating human-Web interaction (HWI), user interface, and
information presentation.
• Nowadays, most Web-based systems are content-driven (database-driven). Web-
based systems development includes creation and management of the content, as
well as appropriate provisions for subsequent content creation, maintenance, and
management after the initial development and deployment on a continual basis (in
some applications as frequently as every hour or more).
• In general, many Web-based systems demand a good “look and feel,” favouring
visual creativity and incorporation of multimedia in presentation and interface. In
these systems, more emphasis is placed on visual creativity and presentation.
• Web applications have a compressed development schedule, and time pressure is
heavy. Hence, a drawn-out development process that could span a few months to
a year or more is not appropriate.
• Ramifications of failure or dissatisfaction of users of Web-based applications can
be much worse than conventional IT systems.
• Web applications are developed by a small team of (often young) people with
diverse backgrounds, skills, and knowledge compared to a team of software
developers. Their perception of the Web and the quality of Web-based systems
also differ considerably, often causing confusion and resulting in misguided
priorities.
• There are rapid technological changes — constant advances in Web technologies
and standards bring their own challenges — new languages, standards, and tools
to cope with; and lots of errors and bugs in early versions of new mark-up
languages, development tools, and environments (technology instability).
• Web development uses cutting-edge, diverse technologies and standards, and
integrates numerous varied components, including traditional and non-traditional
software, interpreted scripting languages, HTML files, databases, images, and
other multimedia components such as video and audio, and complex user interfaces
(Offurt,2002).
• The delivery medium for Web applications is quite different from that of traditional
software. Web applications need to cope with a variety of display devices and
formats, and supporting hardware, software, and networks with vastly varying
access speeds.
• Security and privacy needs of Web-based systems are more demanding than that
of traditional software.
• The Web exemplifies a greater bond between art and science than generally
encountered in software development.
These unique characteristics of the Web and Web applications make Web development
different and more challenging than traditional software development.

Web Engineering 9
Web Engineering
Web engineering is way of developing and organising knowledge about Web application
development and applying that knowledge to develop Web applications, or to address
new requirements or challenges. It is also a way of managing the complexity and diversity
of Web applications.
A Web-based system is a living system. It is like a garden — it continues to evolve,
change, and grow. A sound infrastructure must be in place to support the growth of a
Web-based system in a controlled, but flexible and consistent manner. Web engineering
helps to create an infrastructure that will allow evolution and maintenance of a Web
system and that will also support creativity.
Web engineering is application of scientific, engineering, and management principles
and disciplined and systematic approaches to the successful development, deployment
and maintenance of high quality Web-based systems and applications (Murugesan et
al.,1999).
It is a holistic and proactive approach to the development of large Web-based systems,
and it aims to bring the current chaos in Web-based system development under control,
minimise risks, and enhance the maintainability and quality of Web systems.
Since its origin and promotion as a new discipline in 1998 (Deshpande, Ginige, Murugesan
& Hansen, 2002; Murugesan, 1998), Web engineering is receiving growing interest
among the stakeholders of Web-based systems, including developers, clients, govern-
ment agencies, users, academics, and researchers. In addition, this new field has attracted
professionals from other related disciplines such as multimedia, software engineering,
distributed systems, computer science, and information retrieval.
Web Engineering is Multidisciplinary
Buildingalarge,complexWeb-basedsystemcallsforknowledgeandexpertisefrommany
different disciplines and requires a diverse team of people with expertise in different
areas. Web engineering is multidisciplinary and encompasses contributions from di-
verse areas: systems analysis and design, software engineering, hypermedia/hypertext
engineering, requirements engineering, human-computer interaction, user interface,
information engineering, information indexing and retrieval, testing, modelling and
simulation, project management, and graphic design and presentation.
“Contrary to the perception of some professionals, Web Engineering is not a clone of
software engineering, although both involve programming and software development”
(Ginige & Murugesan, 2001a). While Web Engineering uses software engineering
principles, it encompasses new approaches, methodologies, tools, techniques, and
guidelines to meet the unique requirements of Web-based systems. As previously
stated, development of Web-based systems is much more than traditional software
development. There are subtle differences in the nature and lifecycle of Web-based and
software systems, as well as the way in which they’re developed and maintained. “Web
development is a mixture between print publishing and software development, between

marketing and computing, between internal communications and external relations, and
between art and technology” (Powell, 2000).
Evolution of Web Engineering
Web Engineering is progressively emerging as a new discipline addressing the unique
needs and challenges of Web-based systems development. Since 1998, when the First
Workshop on Web Engineering was held in Brisbane, Australia, in conjunction with the
World Wide Web Conference (WWW7), there has been series of workshops and special
tracks at major international conferences (WWW conferences 1999-2005, HICS 1999-
2001, SEKE 2002 and 2003 and others), and a dedicated annual International Conference
on Web Engineering (ICWE) 2002-2005.
There also have been a few special issues of journals on topics related to Web
Engineering. There are two new dedicated journals, Journal of Web Engineering
(www.rintonpress.com/journals/jweonline.html) and Journal of Web Engineering and
Technology (www.inderscience.com), as well as an edited book, Web Engineering:
Managing Diversity and Complexity of Web Application Development (Murugesan &
Deshpande, 2001).
The bibliography at the end of this chapter gives details of special issues, conferences,
books, and journal articles on Web engineering and other related areas.
New subjects and courses on Web engineering are now being taught at universities, both
at undergraduate and postgraduate levels, and more research is being carried out on
various aspects of Web engineering. Also, not surprisingly, there is growing interest
among Web developers in using Web engineering approaches and methodologies.
Evolutionary Web Development
Web-applications are evolutionary. For many Web applications, it is not possible to
specify fully what their requirements are or what these systems will contain at the start
of their development and later, because their structure and functionality will change
constantly over time. Further, the information contained within and presented by a Web
site often changes — in some applications as often as every few minutes to a couple of
times a day. Thus, the ability to maintain information and to scale the Web site’s structure
(and the functions it provides) is a key consideration in developing a Web application.
Given this Web environment, it seems the only viable approach for developing sustain-
able Web applications is to follow an evolutionary development process where change
is seen as a norm and is catered to. And, this also mandates adoption of a disciplined
process for successful Web development.

Web Engineering 11
Web Development Process
A Web development process outlines the various steps and activities of Web-based
systems development. It should clearly define a set of steps that developers can follow
and must be measurable and trackable (Ginige & Murugesan, 2001c).
Characteristics of Web applications that make their development difficult — and
uniquely challenging — include their real-time interaction, complexity, changeability,
and the desire to provide personalised information. In addition, the effort and time
required to design and develop a Web application is difficult to estimate with a reasonable
accuracy.
Based on our practical experience in building Web applications, we recommend an
evolutionary process for Web development, shown in Figure 2. This process assists
developers in understanding the context in which the application will be deployed and
used; helps in capturing the requirements; enables integration of the know-how from
different disciplines; facilitates the communication among various members involved in
the development process; supports continuous evolution and maintenance; facilitates
easier management of the information content; and helps in successfully managing the
complexity and diversity of the development process (Ginige & Murugesan 2001c).
Context Analysis
The first essential step in developing a Web-based system is “context analysis,” where
we elicit and understand the system’s major objectives and requirements, as well as the
Figure 2. Web development process
Project
Management
Quality
Control
&
Assurance
Context Analysis
Process
Model
System Architecture
Design
Project Plan
Project Plan
Web Site
Development
Web Site
Development
Evaluation &
Maintenance Deployment
Documentation

needs of the system’s typical users and the organisation that needs the system. It is
important to realise at this stage that requirements will change and evolve — even during
system development and after its deployment. It is also important to study briefly the
operation for which a Web application is to be developed, and the potential implications
of introduction of the new system on the organisation. This study should normally
include: how information (to be made available on the Web) is created and managed;
organisational policy on ownership and control (centralised or decentralised) of infor-
mation; its current and future plans and business objectives; possible impact of the
introduction of Web-based applications on the organisation; the resulting changes in
its business and business processes; and emerging trends in the industry sector.
As the Web applications evolve and need to be modified to cater to new requirements
— some of which arise from changes or improvements in the business process as a result
of deployment of the new Web-based system — an understanding of a big picture about
the organisation and its information management policies and practices is a prerequisite
for successful design, development, and deployment of Web-based applications.
Before starting Web development, therefore, developers need to elicit and understand
the system’s major objectives and requirements, gather information about the opera-
tional and application environment, and identify the profile of typical system users.
In addition to the functional requirements, potential demands on the scalability, main-
tainability, availability, and performance of the system need to be specifically elicited and
understood by the developers at the beginning of the development process. Based on
this information, developers then arrive at the system’s functional, technical, and non-
technical requirements, which, in turn, influence the system’s architectural design.
For instance, if the information content and the system’s functions are going to evolve
considerably, like in most e-business systems, the system needs to be designed for
scalability. On the other hand, if the information changes frequently — like in weather
reports, special sales offerings, job vacancies, product price list, brochures, and latest
news or announcements — to keep the information current and consistent, the system
needs to be designed for easy information maintainability (Merialdo et al., 2003).
Moreover, where the application demands very high availability and needs to cater for
high peak or uncertain demands, the system may be required to run on multiple Web
servers with load balancing and other performance enhancement mechanisms (Almedia
&Menasce,2002;Menasce&Almedia,2002;Oppenheimer&Patterson,2002).Examples
of this category of applications are online stock trading, online banking, and high volume
near-real-time sports and entertainment Web sites such as the Olympics, Wimbledon,
and Oscar Web sites.
Thus, it is very important to recognise that scalability, maintainability, and/or perfor-
mance need to be built into the initial system architecture. It would be very hard, or
impossible, to incorporate these features if the initial architecture is not designed to
support them. To illustrate this, consider an e-business Web site that provides product
information, such as price and availability, which appears on many different pages and
changes frequently. If the Web site is designed as static Web pages, then every time a
product’s information changes, one has to incorporate the change in every page that
contains this information. This is a cumbersome and laborious task, and often changes
are only made to a few pages, instead of all relevant pages. As a consequence of this,
the same information appearing on different pages will be inconsistent.

Web Engineering 13
A better approach to ensure consistency of information across all Web pages is to
automatically retrieve the information, when and where needed, from a single information
source. If product information is stored in a single central database, then by extracting
the relevant information from this database, we can dynamically create various Web
pages that contain this information. In the database-driven approach, we need to change
the information only in one place: the database. Further, the database-driven Web sites
can have a back-end system to allow an authorised person, who may not be skilled in Web
page development, to make information changes easily through a Web interface, from
anywhere. A database-driven Web site requires a completely different architecture than
a Web site that has only static Web pages. Hence, an appropriate architecture that would
meet the system’s requirements needs to be chosen early in the system development.
Thus, as highlighted in Table 2, the objective of context analysis is to capture and derive
the key information required to develop the Web application. In addition, it can also
identify non-technical issues that have to be addressed for successful implementation
and application of the system. These may include reengineering of business processes
where required, organisational and management policies, staff training, and legal,
cultural and social aspects.
Context analysis can minimise or eliminate the major problems plaguing large Web-based
system development. But, many developers and project managers overlook this essential
first step in Web system development and face the problems later when it is hard to correct
them.
Based on the context analysis, we then arrive at the system’s technical and non-technical
requirements (Lowe, 2003), which, in turn, influence the system architecture design.
Architecture Design
In system architecture design, we decide on various components of the system and how
they are linked. At this stage, we design:
Table 2. Objectives of context analysis of Web applications
The objectives of context analysis, the first step in Web development, are to:
§ Identify the stakeholders and their broader requirements and experiences.
§ Identify the functions the Web site needs to provide (immediately, and in the
short, medium, and long term).
§ Establish what information needs to be on the Web site, how to get this
information, and how often this information may change.
§ Identify the corporate requirements in relation to look and feel, performance,
security, and governance.
§ Get a feel of the number of users (typical and peak) and anticipated demands on
the system.
§ Study similar (competitive) Web sites to gain an understanding of their
functionalities, strengths, and limitations.

• An overall system architecture describing how the network and the various servers
(Web servers, application servers and database servers) interact;
• An application architecture depicting various information modules and the func-
tions they support; and
• A software architecture identifying various software and database modules re-
quired to implement the application architecture.
Table 3 summarises the means of fulfilling some of the requirements of Web-based
applications (Ginige & Murugesan, 2001c).
We then decide on an appropriate development process model (Uden, 2002; Pressman,
2004) and develop a project plan. To successfully manage Web development, a sound
project plan and a realistic schedule are necessary. Progress of development activities
must be monitored and managed. Project planning and scheduling techniques that are
commonly used in other disciplines can be used for Web development. Following this,
the various components of the system and Web pages are designed, developed and
tested.
Table 3. Means of fulfilling the requirements of Web application
Requirement Means of Fulfilment
Uniform look and feel across all Web pages that can
easily be modified
Creation of Web pages using templates and
style sheets
Consistency of information that may appear in
different places or pages
Storing information in a single place (such as
in a database or as an XML file), without
duplication of information in different places
or databases, and retrieving the required
information for presentation where and when
needed
Ease of information update and maintenance Provision of a back-end system to edit
information in a data repository; could have
Web interface for easy access from anywhere
Ability to add new Web pages easily Dynamic generation of navigational links,
rather than predetermined static navigational
links
Decentralised system administration Provision of a multi-user login system to
access back-end systems and inclusion of a
“user administration system” that can assign
specific functions and data sets to content
managers and other developers/administrators
Mechanisms for quality control and assessing the
relevance of information
Inclusion of metadata for Web pages; use of a
Web robot for gathering salient information,
processing the information gathered and
taking appropriate action(s) for ensuring
quality or relevance of information presented.
Increased probability of being found through search
engines
Using meta tags and registering with search
engines

Web Engineering 15
Web Page Design
Web page design is an important activity; it determines what information is presented
and how it is presented to the users. A prototype usually contains a set of sample pages
to evaluate the page layout, presentation, and navigation (within and among different
pages). Based on the feedback from the stakeholders, the page design is suitably
modified. This process may go through a few iterations until the stakeholders and
designers are satisfied with the page layout, presentation and the navigation structure.
Web page content development needs to take into consideration the stakeholders’
requirements, users’ cognitive abilities (Cloyd, 2001), technical issues and consider-
ations, nontechnical issues, earlier experiences of developers and users, and lessons
learned from similar Web applications (Figure 3).
If the Web system is intended for global use, by users from different countries, the Web
content and presentation may have to be localised; there also may be a need for
multilingual Web sites (for details, see Becker & Mottay, 2001; Collins, 2002). Also, the
Web site’s content and usability have to be designed from a global perspective and be
responsive to cultural sensitivity in language along with appropriate use of colour,
presentation, and animation (Becker & Mottay, 2001).
Web Maintenance
After a Web-based system is developed and deployed online for use, it needs to be
maintained. As outlined earlier, content maintenance is a continual process. We need to
formulate content maintenance policies and procedures, based on the decision taken at
the system architecture design stage on how the information content would be main-
Figure 3. Web page design
Web Page
Design
Technology
Constraints
Information
Structure
Information
Access Methods
Look & Feel
Guidelines for
Content
Development
Users’ Cognitive
Skills & Abilities
Nontechnical
considerations
Stakeholder
Requirements
Experience of
Users and
Developers
Lessons Learned
Web Page
Design
Technology
Constraints
Information
Structure
Information
Access Methods
Look & Feel
Guidelines for
Content
Development
Users’ Cognitive
Skills & Abilities
Nontechnical
considerations
Stakeholder
Requirements
Experience of
Users and
Developers
Lessons Learned

tained, and then we need to implement them. Further, as the requirements of Web systems
grow and evolve, the system needs to be updated and also may be redesigned to cater
to the new requirements.
It is important to periodically review Web-based systems and applications regarding the
currency of information content, potential security risks, performance of the system, and
usage patterns (by analysing Web logs), and take suitable measures to fix the shortcom-
ings and weaknesses, if any.
Project Management
The purpose of project management is to ensure that all the key processes and activities
work in harmony. Building successful Web-based applications requires close coordina-
tion among various efforts involved in the Web development cycle. Many studies,
however, reveal that poor project management is the major cause of Web failures both
during development and subsequently in the operational phase. Poor project manage-
ment will defeat good engineering; good project management is a recipe for success.
Successfully managing a large, complex Web development is a challenging task requiring
multidisciplinary skills and is, in some ways, different from managing traditional IT
projects.
Quality control, assurance and documentation are other important activities, but they are
often neglected. Like project management, these activities need to spread throughout the
Web development lifecycle.
Steps to Successful Development
Successful development of Web systems and applications involves multiple interactive
steps which influence one another. We recommend the following key steps for success-
ful development and deployment of Web applications (Ginige & Murugesan, 2001c):
1. Understand the system’s overall function and operational environment, including
the business objectives and requirements, organisation culture and information
management policy.
2. Clearly identify the stakeholders — that is, the system’s main users and their
typical profiles, the organisation that needs the system, and who funds the
development.
3. Elicit or specify the (initial) functional, technical, and nontechnical requirements
of the stakeholders and the overall system. Further, recognise that these require-
ments may not remain the same; rather, they are bound to evolve over time during
the system development.
4. Develop overall system architecture of the Web-based system that meets the
technical and nontechnical requirements.

Web Engineering 17
5. Identify subprojects or subprocesses to implement the system architecture. If the
subprojects are too complex to manage, further divide them until they become a set
of manageable tasks.
6. Develop and implement the subprojects.
7. Incorporate effective mechanisms to manage the Web system’s evolution, change,
and maintenance. As the system evolves, repeat the overall process or some parts
of it, as required.
8. Address the nontechnical issues, such as revised business processes, organisa-
tional and management policies, human resources development, and legal, cultural,
and social aspects.
9. Measure the system’s performance, analyse the usage of the Web application from
Web logs, and review and address users’ feedback and suggestions.
10. Refine and update the system.
Web System Design: Challenges
The Internet is an open platform that provides unparalleled opportunities. But it has
virtually no control over visitor volume, or when and how they access a Web system.
This makes developing Web applications that exhibit satisfactory performance even
under a sudden surge in number of users a nebulous and challenging task.
Satisfying the expectations and needs of different types of users with varying skills is
not easy. When users find a site unfriendly, confusing, or presented with too much
information, they will leave frustrated. Worse yet, these frustrated users may spread the
bad news to many others. Web site usability factors include good use of colours,
information content, easy navigation, and many more. They also include evaluation from
an international perspective so that you can reach a global audience. Web usability
factors that impact the Web user experience are (Becker & Berkemeyer, 2002): page
layout, design consistency, accessibility, information content, navigation,
personalisation, performance, security, reliability, and design standards (naming con-
ventions, formatting, and page organisation).
A Web-based system also has to satisfy many different stakeholders besides the diverse
range of users, including: persons who maintain the system, the organisation that needs
the system, and those who fund the system development. These may pose some
additional challenges to Web-based system design and development.
Today’s Web-savvy consumers do not tolerate much margin of error or failure. Web
system slow down, failure, or security breach may cause a loss of its customers —
probably permanently. A whopping 58 percent of first time customers would not return
to a site that crashed (Electronic Hit and Run, USA Today, 10 Feb 2000). According to
a study (Inter@ctive Week, 6 Sep 1999), US$4.35 billion may be lost in e-business due
to poor Web download speeds alone.

As Web applications are becoming mission-critical, there is greater demand for improved
reliability, performance, and security of these applications.
Poor design and infrastructure have caused many Web applications to be unable to
support the demands placed on them, so they have therefore failed. Many Web sites have
suffered site crashes, performance failures, security breaches, and outages — resulting
in irate customers, lost revenue, devalued stocks, a tarnished reputation (bad publicity,
lack of customer confidence), permanent loss of customers, and law suits (Williams,
2001). Stock prices have become inextricably linked to the reliability of a company’s e-
commerce site.
The recent major failures and their impact on enterprises have served as a forceful
reminder of the need for capacity planning, and improved performance, quality, and
reliability. Successful Web application deployment demands consistent Web site
availability, a better understanding of its performance, scalability, and load balancing.
Proactive measures are needed to prevent grinding halts and failures from happening in
the first place.
Large-scale Web system design is a complex and a challenging activity as it needs to
consider many different aspects and requirements, some of which may have conflicting
needs (Ivory & Hearst, 2002; Siegel, 2003; Cloyd, 2001).
We use terms like scalability, reliability, availability, maintainability, usability, and
security to describe how well the system meets current and future needs and service-level
expectations. These -ilities characterise (Williams, 2000) a Web system’s architectural
and other qualities. In the face of increasingly complex systems, these system qualities
are often more daunting to understand and manage.
Scalability refers to how well a system’s architecture can grow, as traffic, demand for
services, or resource utilisation grows. As Web sites grow, small software weaknesses
that had no initial noticeable effects can lead to failures, reliability problems, usability
problems, and security breaches. Developing Web applications that scale well repre-
sents one of today’s most important development challenges.
Flexibility is the extent to which the solution can adapt as business requirements change.
A flexible architecture facilitates greater reusability and quicker deployment.
Thus, the challenge is to design and develop sustainable Web systems for better:
• Usability — interface design, navigation (Becker & Mottay 2001),
• Comprehension,
• Performance — responsiveness,
• Security and integrity,
• Evolution, growth, and maintainability, and
• Testability.

Web Engineering 19
Web Testing and Evaluation
Testing plays a crucial role in the overall development process (Becker & Berkemeyer,
2002; Hieatt & Mee, 2002; Lam, 2001). However, more often than not, testing and
evaluation are neglected aspects of Web development. Many developers test the system
only after it had met with failures or limitations have become apparent, resorting to what
is known as retroactive testing. What is desired in the first place is proactive testing at
various stages of the Web development lifecycle. Benefits of proactive testing include
assurance of proper functioning and guaranteed performance levels, avoidance of costly
retroactive fixes, optimal performance, and lower risk.
Testing and validating a large complex Web system is a difficult and expensive task.
Testing should not be seen as a one-off activity carried out near the end of development
process. One needs to take a broad view and follow a more holistic approach to testing
— from design all the way to deployment, maintenance, and continual refinement.
The test planning needs to be carried out early in the project lifecycle. A test plan
provides a roadmap so that the Web site can be evaluated through requirements or design
stage. It also helps to estimate the time and effort needed for testing — establishing a
test environment, finding test personnel, writing test procedures before any testing can
actually start, and testing and evaluating the system.
Lam (2001) groups Web testing into the following broad categories and provides
excellent practical guidelines on how to test Web systems:
• Browser compatibility
• Page display
• Session management
• Usability
• Content analysis
• Availability
• Backup and recovery
• Transactions
• Shopping, order processing
• Internalisation
• Operational business procedures
• System integration
• Performance
• Login and security

Experience shows that there are many common pitfalls in Web testing and attempts
should be made overcome them (Lam, 2001). Testing and evaluation of a Web application
may be expensive, but the impact of failures resulting from lack of testing could be more
costly or even disastrous.
Knowledge and Skills for
Web Development
The knowledge and skills needed for large, complex Web application development are
quite diverse and span many different disciplines. They can be broadly classified as:
• Technologies supporting and facilitating Web applications
• Design methods
• Design for usability — interface design, navigation
• Design for comprehension
• Design for performance — responsiveness
• Design for security and integrity
• Design for evolution, growth and maintainability
• Design for testability
• Graphics and multimedia design
• Web page development
• System architecture
• Web development methods and processes
• Web project management
• Development tools
• Content management
• Web standards and regulatory requirements
Web Development Team
As previously mentioned, development of a Web application requires a team of people
with diverse skills and backgrounds (Hansen, 2004). These individuals include program-
mers, graphic designers, Web page designers, usability experts, content developers,

Web Engineering 21
database designers and administrators, data communication and networking experts, and
Web server administrators. A Web development team is multidisciplinary, like a film
production team, and must be more versatile than a traditional software development
team.
Hansen et al. (2001) presents a classification of the participants in a Web development
team and a hierarchy for their skills and knowledge. This classification helps in forming
a team and in devising a strategy for successful reskilling of the development team.
Conclusion
Web engineering is specifically targeted toward the successful development, deploy-
ment and maintenance of large, complex Web-based systems.
It advocates a holistic and proactive approach to developing successful Web applica-
tions. As more applications migrate to the Web environment and play increasingly
significant roles in business, education, healthcare, government, and many day-to-day
operations, the need for a Web engineering approach to Web application development
will only increase. Further, as we now place greater emphasis on the performance,
correctness, and availability of Web-based systems, the development and maintenance
process will assume greater significance.
Web Engineering is an emerging discipline having both theoretical and practical
significance. It is gaining the interest among researchers, developers, academics, and
clients. This is evidenced by increased research activities and publications in this area,
hosting of dedicated international conferences and workshops, publication of new
journals devoted to Web Engineering, and universities offering special courses and
programmes on the subject. It is destined for further advancement through research,
education, and practice.
“To advance Web engineering, it is essential to define its core body of
knowledge, to identify the areas in need of greater research and to develop
a strategy to tackle the new technologies, new applications and the various
technical, methodological, and societal issues that arise in tandem with
such developments.” (Deshpande, Olsina & Murugesan, 2002)
Some of the areas that need further study, in no particular order, include:
• Web application delivery on multiple devices — desktop and pocket PCs, mobile
phones, PDAs, TVs and refrigerators
• Context-aware Web applications and context-sensitive responses
• Device-independent Web access and content presentation

• Modelling and simulation of Web applications and systems
• Performance evolution and enhancement
• Testing and validation of systems
• Effort and cost estimation
• Web personalisation
• Quality control and assurance
No Silver Bullet!
Web Engineering will not make the problems and the risks go away. But, it can help you
plan, monitor, control, and cope with the challenging task of developing large, complex
Web applications. It will also facilitate making more informed decisions and developing
better quality and better-engineered Web systems and applications.
It is important to understand the wider context in which a Web-based system or
application will be used, and design an architecture that will support the development,
operation, and maintenance as well as evolution of the Web application in that context,
addressing the key issues and considerations. We strongly recommend that Web
developers and project managers move away from an ad hoc, hacker-type approach to
a well-planned, systematic, and documented approach for the development of large,
high-performance, evolutionary, and/or mission-critical Web sites and applications.
Our key recommendations for successfully developing and implementing large, complex
Web application are to:
• Adopt a sound strategy and follow a suitable methodology to successfully manage
the development and maintenance of Web systems.
• Recognise that, in most cases, development of a Web application is not an event,
but a process, since the applications’ requirements evolve. It will have a start, but
it will not have a predictable end as in traditional IT/software projects.
• Within the continuous process, identify, plan, and schedule various development
activities so that they have a defined start and finish.
• Remember that the planning and scheduling of activities is very important to
successfully manage the overall development, allocate resources, and monitor
progress.
• Consider the big picture during context analysis, planning, and designing a Web
application. If you do not, you may end up redesigning the entire system and
repeating the process all over again. If you address the changing nature of
requirements early on, you can build into the design cost-effective ways of
managing change and new requirements.

Web Engineering 23
• Recognise that development of a large Web application calls for teamwork and
shared responsibility among the team members, so motivate a team culture.
Web engineering has been successfully applied in a number of Web applications. A well-
engineered Web system is:
• Functionally complete and correct
• Usable
• Robust and reliable
• Maintainable
• Secure
• Perform satisfactorily even under flash and peak loads
• Scalable
• Portable, where required perform across different common platforms; compatible
with multiple browsers
• Reusable
• Interoperable with other Web and information systems
• Universal accessibility (access by people with different kinds disabilities)
• Well-documented
Time to deploy an online Web system, though still important, is no longer a dominant
process driver, as more emphasis is now placed on quality Web systems in terms of
functionally, usability, content maintainability, performance, and reliability.
Web engineering can help enterprises and developers to convert their Web systems and
applications from a potential costly mess into powerful resource for gaining sustainable
competitive advantage.
Acknowledgments
The authors would like to thank Yogesh Deshpande and Steve Hansen, both from
University of Western Sydney, Australia, for their contribution in origination and
development of the Web engineering discipline and for their input on various aspects
of Web development reported in this chapter which evolved through our collaborative
efforts over the years. We would also like to thank our graduate students Anupama
Ginige and Indra Seher who contributed to formulation and presentation some of the
ideas presented in this chapter.

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Bibliography on Web Engineering
For further information on many different aspects of Web development and Web
Engineering, we have listed below some useful resources such as books, special issues,
journal articles, and Web sites.

Books
Burdman, J. (1999). Collaborative Web development: Strategies and best practices for
Web teams. Addison-Wesley.
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Norwood, MA: Arttech House.
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Menasce, D.A. & Almeida, V.A.F. (2002). Capacity planning for Web services: Metrics,
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Nakano, R. (2002). Web content management: A collaborative approach. Boston:
Addison Wesley.
Nguyen, H. Q. (2001). Testing applications on the Web: Test planning for Internet-based
systems. John Wiley.
Nielsen, J. (1999). Designing Web usability: The practice of simplicity. Indianapolis, IN:
New Riders Publishing.
Powell, T.A. (1998). Web site engineering: Beyond Web page design. Upper Saddle River,
NJ: Prentice Hall.
Powell, T.A. (2000). Web design: The complete guide. New York: McGraw-Hill.
Pressman, R.S. (2004). Applying Web engineering. In Software engineering: A
practitioner’s perspective. New York: McGraw-Hill.
Rosenfeld, L. & Morville, P. (2002). Information architecture for the World Wide Web:
Designing large-scale Web sites. O’Reilly & Associates.
Scharl, A. (2000). Evolutionary Web Development. Springer.
Shklar, L. & Rosen, R. (2003). Web application architecture: Principles, protocols and
practices. John Wiley & Sons.
Stottlemyer, D. (2001). Automated Web testing toolkit: Expert methods for testing and
managing Web applications. John Wiley.
Vidgen, R. et al (2002). Developing Web information systems: From strategy to imple-
mentation. Butterworth Heinemann.
Wodtke, C. (2002). Information architecture: Blueprints for the Web. New Riders.

Web Engineering 27
Journals
IEEE Internet Computing. www.computer.org/internet
IEEE Software. www.computer.org/software
Journal of Web Engineering, Rinton Press. www.rintonpress.com/journals/jwe
Journal of Web Engineering and Technology. www.inderscience.com
Web Information Systems Engineering. http://www.i-wise.org
World Wide Web, Kluwer Academic Publishers. http://www.kluweronline.com/issn/
1386-145X
Special Issues
Engineering Internet Software, IEEE Software, March-April 2002.
Testing E-business Applications, Cutter IT Journal, September 2001.
Usability and the Web, IEEE Internet Computing, March-April 2002.
Usability Engineering, IEEE Software, January-February 2001.
Web Engineering, Cutter IT Journal, 14(7), July 2001.
Web Engineering, IEEE MultiMedia, Jan.–Mar. 2001 (Part 1) and April–June 2001 (Part
2).
Journal Articles
Almedia, V.A.F., & Menasce, D.A. (2002). Capacity planning for Web services: An
essential tool for managing Web services. ITPro, July-August 2002, 33-38.
Arlitt, M., et al. (2001). Characterizing the scalability of a large Web-based shopping
system. ACM Transactions on Internet Technology, 1(1), 44-69.
Barnes, S. & Vidgen, R. (2002). An integrative approach to the assessment of e-commerce
quality.JournalofElectronicCommerceResearch,3(3).http://www.webqual.co.uk/
papers/jecr_published.pdf
Baskerville. et al. (2003). Is Internet-speed software development different? IEEE
Software, Nov-Dec, 70-77.
Becker, S. & Mottay, F. (2001). A global perspective of Web usability for online business
applications. IEEE Software, 18(1), 54-61.
Brewer, E.A. (2002). Lessons from giant-scale services. IEEE Internet Computing, July,
46-55.
Cardellini, V. et al. (1999). Dynamic balancing on Web server systems. IEEE Internet
Computing, May-June, 2839.
Ceri, S., Fraternali, P., & Bongio, A. (2000, May). Web modelling language (WebML): A
modelling language for designing Web sites. Proceedings of the World Wide Web
WWW9 Conference, Amsterdam.
Cloyd, M.H. (2001). Designing user-centered Web applications in Web time. IEEE
Software, 18(1), 62-69.

Collins, R.W. (2002). Software localization for Internet software: Issues and methods.
IEEE Software.
Davison, B.D. (2002). A Web catching primer. IEEE Internet Computing.
Deshpande et al. (2002). Web engineering. Journal of Web Engineering, 1(1), 3-17.
Deshpande, Y. et al. (2002). Consolidating Web engineering as a discipline. SEA
Software.
Deshpande, Y. et al. (2002, July). Web site auditing – The first step towards reengineering.
Proc 14th
International Conference on Software Engineering and Knowledge
Engineering, Italy, 2002, pp. 731 – 737.
Deshpande, Y. & Hansen, S. (2002). Web Engineering: Creating a discipline among
disciplines. IEEE Multimedia, 82-87.
Fewster, R. & Mendes, E. (2001, April 4-6). Measurement, prediction and risk analysis
for Web applications. IEEE Seventh International Software Metrics Symposium
London, England, pp. 338-348.
Ginige, A. & Murugesan, S. (2001) Web engineering: An introduction. IEEE Multimedia,
8(1),14-18.
Ginige, A. & Murugesan, S. (2001). Web engineering: A methodology for developing
scalable, maintainable Web applications. Cutter IT Journal, 14(7) 24–35.
Ginige, A. & Murugesan, S. (2001). The essence of Web engineering: Managing the
diversity and complexity of Web application development. IEEE Multimedia, 8(2),
22-25.
Glass, R. Who’s right in the Web development debate? Cutter IT Journal, 14(7), 6-10.
Goeschka, K.M. & Schranz, M.W. (2001). Client and legacy integration in object-oriented
Web engineering. IEEE Multimedia, Special issues on Web Engineering, 8(1), 32-
41.
Hieatt, E. & Mee, R. (2002). Going faster: Testing the Web application. IEEE Software,
60-65.
Ingham, D.B., Shrivastava, S.K., & Panzieri, F. (2000). Constructing dependable Web
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56-63.
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19-27.
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8,102-113.

Web Engineering 29
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43.
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Pressman, R.S. (2001). Can Internet-based applications be engineered? IEEE Software,
15(5),104-110.
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ware.
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IEEE Software, 34-41.
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design. Theory and Practice of Object Systems (TAPOS), special issue on the
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for reuse. IEEE Multimedia, 8(1), 20-31.
Scott, D., & Sharp, R. (2002). Developing secure Web applications, IEEE Internet
Computing, 38-45.
Siegel, D.A. (2003). The business case for user-centred design: Increasing your power
of persuasion. Interactions, 10(3).
Upchurch, L. et al. (2001). Using card sorts to elicit Web page quality attributes. IEEE
Software.
Williams, J. (2000). Correctly assessing the “ilities” requires more than marketing hype.
IT Professional, 2(6), 65-67.

Web sites
ACMSIGWEB:www.acm.org/sigweb
Jakob Nielsen’s Website: www.useit.com
NIST Web Usability: zing.ncsl.nist.gov/WebTools/index.html
Universal Usability Guide: www.universalusability.org
Usability Professional Association: www.upassoc.org
Usable Web: www.usableweb.com
Web Engineering Resources, R.S. Pressman and Associates: www.ispa.com/spi/
index.html#webe
Web Engineering.org Community Homepage: www.webengineering.org
Web Information System Development Methodology: www.wisdm.net
Web Information Systems Engineering: http://www.i-wise.org
Web Quality: www.webqual.co.uk
World Wide Web Consortium: www.w3.org
Conferences
InternationalConferenceonWebEngineering(ICWE)2004and2005. www.icwe2004.org;
www.icwe2005.org
Web Information Systems Engineering Conference. http://www.i-wise.org/
World Wide Web Conference. www.www2004.org; www.www2005.org

WEP: The Web Engineering Resources Portal 31
Chapter II
WebEngineering
ResourcesPortal(WEP):
A Reference Model and Guide
Sotiris P. Christodoulou
University of Patras, Greece
Theodore S. Papatheodorou
University of Patras, Greece
Abstract
This chapter introduces the Web Engineering Resources Portal (WEP) as a basic
reference model and guide for Web Engineers. WEP provides a general classification
of Web Engineering resources under technologies, research results, and tools. It
consists of a reference model and a resources portal. The objective of the WEP reference
model is to provide a common basic terminology, a technical-oriented classification
of Web applications (WebApps), a specification of WebApps Logical and Physical
Architectures, a classification of skills needed in Web projects and a generic and
adaptableWeblifecycleprocessmodel.TheWEPreferencemodelprovidestheframework
upon which Web Engineering resources are classified and presented. The WEP portal
provides several and cross-referenced taxonomies of technologies, research results,
and tools whereas its objective is to facilitate Web Engineers to comprehend available
resources, understand their role and appropriately use them during development and
operation/maintenance of Web information systems.

32 Christodoulou and Papatheodorou
Introduction
Web Engineering is defined in Deshpande, Murugesan, Ginige, Hansen, Schwbe, Gaedke
and White (2002), by experienced researchers in the field as: “The application of
systematic, disciplined and quantifiable approaches to development, operation, and
maintenance of Web-based Information Systems (WIS). It is both a pro-active approach
and a growing collection of theoretical and empirical research in Web application
development.” In the same work, Web engineering is essentially defined as “matching
the problem domains properly to solution methods and the relevant mix of technologies”
(Deshpande et al., 2002).
But, what is WIS1
? Holck (2003) provides a good survey of WIS definitions around the
literature, where there is some confusion because of diverse perspective and terms used.
Thus, we conclude that the first thing Web Engineers really need is a common terminol-
ogy on WIS and its components. To address this need, we include in the WEP Reference
Model a specific part entitled: WEP-Terms: WEP Basic Terminology & Definitions. We
replicate the definitions of WIS and Web applications here as well.
WIS is an information system utilizing Web technologies to provide information (data)
and functionality (services) to end-users through a hypermedia-based presentation/
interaction user interface on web-enabled devices.
WebApps are the different functionality-oriented components of a WIS. A WebApp is
actually a small-scale WIS, providing very specific information or functionality. Many
developers use these terms as synonymous, especially for small WISs.
Moreover, we define the “planning, development, operation, and maintenance of WIS”
as a Web project. Basically, it is a lifecycle process model to ensure successful WIS
development and evolving through a number of stages from investigation of initial
requirements through analysis, design, implementation, testing, and operation/mainte-
nance.
In each stage, the process model specifies the activities that are carried out, the
relationships between these activities, the skills needed (roles), the resources that are
used, the results that are created, etc. The activities are carried out by teams of developers
who are based on selected Web technologies, take advantage of selected research
results, and use a number of tools. This triplet constitutes the Web Engineering
Resources (WER), which includes anything available to developers to support the Web
project. Figure 1 shows how they are produced and related to each other. However, WERs
are not easily discoverable and understandable by developers, so they are often not used
appropriately or at all during the Web projects for reasons outlined in the next section.
The main objective of this chapter is to put Web Engineering Resources in use and to
provide a reference model and guide for Web Engineers. We call it the Web Engineering
Resources Portal (shortly WEP), because it provides several and cross-referenced
taxonomies of these resources, just like an information portal does. WEP provides a WEP
reference model and WER portal. The WEP reference model includes:

(a) WEP-Terms: WEP basic terminology and definitions. We define the main terms
used in WEP in order to determine the semantics of the terms used in it.
(b) WEP-Arch: Identification and technical-oriented classification of common WIS
components (namely WebApps). Specification of the three WebApps’ logical
layers: content, logic and interface, and the WebApps’ physical architecture.
(c) WEP-Teams: Specification and classification of skills needed in the WIS project
under abstract team classes of stakeholders.
(d) WEP-Process: A WIS lifecycle process model with three phases: planning,
deployment and evolution. It is a generic process model through which WEP-
Teams are using WERs to deliver and maintain a WIS based on the WEP-Arch. We
keep this high-level process generic, easy for the developers to follow, compre-
hend and adapt to specific WIS requirements.
(e) WER-Portal: Several Web Engineering Resources taxonomies through which
Web engineers will be able to easily and meaningfully locate research resources,
web technologies, and tools and understand their role during WIS development
and WIS operation/maintenance. The objective of the WER portal is to help Web
Engineers to comprehend and appropriately use available and emerging Web
technologies/tools and to provide means to transfer knowledge (research results)
and experience (patterns/good practices) in an easy and understandable way. The
WER portal should be regularly updated in order to include new WERs.
Background: Web Development Status
“Web development” is a global term used for development of either a few HTML pages
or a large-scale WIS. Moreover, the word “development” refers only to design and
implementation issues, while the lifecycle of a WIS is bigger. Thus, we usually prefer
Figure 1. Web engineering resources
Web Engineering Resources
Research Results
(Theoretical & Empirical)
Standards Bodies
(IETF, W3C, etc.)
Researchers &
Practitioners
S/W Companies
OpenSource Orgs.
Researchers
Individuals
Web Technologies
Tools
Web
Engineers
WIS
INPUT
OUTPUT
Tools

using the term “Web project” instead. Moreover, instead of “Web developer” we often
use the term “Web Engineer” whenever we have to emphasize the strong engineering
skills needed.
In the literature (Holck, 2003) concerning Web development, quite a number of special
characteristics (comparing to other information systems) have been addressed. Four of
the perhaps most often mentioned are: the new, incremental development process, the
time pressure, the new professions, and a diverse and remote user group. Some other
special characteristics include: a much more fine-grained ongoing maintenance process
(actually an evolution), strong integration requirements with legacy systems, unpredicted
end-users and an emphasis on the content (content management and personalized/
adaptive information). For more information on the topic refer to Deshpande et al. (2002).
To address these special characteristics, several Web-oriented lifecycle processes have
been proposed. Some of them come from the area of software engineering and are tailored
to the WIS special needs (we provide the taxonomy of them inside WEP). A Web
Engineer’s first choice for a Web project is the lifecycle process among many and similar
ones. Additionally, in several stages of the process, they also must choose among
several software tools, technologies, and research resources. Especially when it comes
to the implementation phase, several issues concerning Web technologies are coming
up, and Web Engineers has to carefully pick the right ones.
The problem is getting even bigger if we consider that tools and technologies (i.e.,
standards) are shifting extremely fast in the Web world and their volume is big. As
Nambisan and Wang (1999) state, “Technology-related knowledge barriers are intensi-
fied by the fact that much of the Web technologies are not yet mature, making the task
of choosing from among alternative technological solutions a challenging one.” Further-
more, Web projects span a variety of application domains and involve stakeholders of
different backgrounds. Thus, they have very different requirements for methodologies,
tools and technologies, even for different parts of the same WIS.
Finally, some research results, like Hansen, Deshpande and Murugesan (2001) specify
required skills for developers working on different parts of WIS development. However,
many real projects today are carried out with crucial roles or skills missing. Thus,
unskilled or inexperienced developers need help to quickly understand what Web
Engineering can offer to them.
Conclusions
Based on our extended experience for several years on building large-scale Web-based
systems and on our studies and research (Christodoulou, Styliaras & Papatheodorou,
1998; Christodoulou, Zafiris & Papatheodorou, 2001) and above analysis, we have
concluded the following:
• In several stages of all proposed Web development processes, developers are
asked to consider carefully and choose correctly the appropriate technologies to
base on their development. However, these processes are not providing any way

to help achieve it. They assume that developers have the appropriate technology
knowledge and experience, but this is not true for most Web developers.
• Very few research results are transferred to real-life projects. Web Engineers need
time to study all research results in the fields of Web Engineering and others
affecting it, like multimedia, data management, software engineering, network
engineering, etc.
• Emerging technologies are often used hesitantly in the beginning, and it takes a
lot of time for them to be adopted by a large part of web development community.
Developers need time to study and understand new emerging technologies in such
a broad field.
• Developers need time to use and understand new tools, like development platforms
and emerging languages.
It is clear that Web Engineers have to continually be in a process of studying,
understanding, using, and testing emerging tools and technologies. They need to
exhaustively study the recent research results, in order to gain the knowledge, experi-
ence, and skills to decide correctly. This is a very time consuming task and it is very
difficultformostWebEngineerstofollowinthestricttimelineofaWebproject.Theeffect
of this is the fact that WERs are not used appropriately or at all during current WIS
projects. Cutter Consortium (2000) provides some statistical data on Web projects that
prove this.
We strongly believe that there are solutions out there but are not easily discoverable and
understandable by Web Engineers. Web Engineers need help and guidance in accessing
the knowledge and experience of web development. Current solutions include: design
patterns, good practices, and tutorials on technologies and tools. What is missing is an
overall view and structure of WERs under several taxonomies that helps you find what
you need, and then you have to study and explore it yourself. By studying WERs, we
concluded that there is a very complex information space that needs to be engineered,
in order to provide WERs to developers through a meaningful way. To this end we
introduce WEP.
WEP Reference Model
The objective of the WEP reference model is to provide a common basic terminology
(WEP-Terms), a technical-oriented classification of WebApps, a specification of
WebApps logical and physical architectures (WEP-Arch), a classification of skills
needed in WIS Project (WEP-Teams), and a generic and adaptable WIS lifecycle process
model (WEP-Process) through which WEP-Teams are using WERs to deliver, maintain
and evolve a WIS based on the WEP-Arch. This reference model will provide the base
and framework on which the WERs will be classified and presented.

WEP-Terms: WEP Basic Terminology and Definitions
Throughout this chapter, several Web and non-Web terms are used. In order for the
readers to perceive the concepts outlined in this chapter, we have to share the same
understanding of basic terms. Let us start by defining the general terms: data, informa-
tion, software, program and application.
Anything that can be stored electronically is either data or software.
Data2
are distinct pieces of information in digital form, formatted in a special way that can
be read, manipulated, or transmitted on some digital channel by software. Data can be
related with other data. These relations or links are part of the data that facilitate its
efficient manipulation. Data on its own has no meaning. Only when interpreted by some
kind of data processing system does it take on meaning and become information. People
or computers can find patterns in data to perceive information, and information can be
used to enhance knowledge.
Software is a collection of instructions in a form that can be read and executed by a
computer. Software can be divided in two general categories: systems software and
programs (application software). Systems software includes the operating system and
all the utilities that enable the computer to function and support the production and
execution of programs.
An application is a composition of one or more programs that do real work for humans.
One of the programs is responsible for providing the user interface, through which
humans can interact with the application, in order to generally do two things: (1) get data
as information (specific programs to read, listen, or watch data) or (2) get functionality
over data as services.
Figure 2 visualizes the meaning of some of the above terms. The following Web-oriented
terms are used here as defined in W3C “Web Characterization Terminology & Definitions
Sheet3
” (W3C Working Draft 24-May-1999): URI, link, anchor, user, Web client, Web
request, explicit Web request, implicit Web request, Web server, Web response, cookie,
Web resource, Web page, and Web site. We suggest studying these definitions before
reading this chapter.
Web Architecture4
The World Wide Web, known as “WWW”, “the Web” or “W3”) as defined by W3C, is
“the universe of network-accessible information, available through Web-enabled de-
vices, like computer, phone, television, or networked refrigerator.” The Web is a network-
spanning information space in which the information objects, referred to collectively as
Web resources, are identified by global identifiers called URIs and are interconnected by
links defined within that space.
A Web agent is software acting on this information space on behalf of a person, entity,
or process. Agents include servers, proxies, browsers, spiders, multimedia players, and
other user agents.

Web architecture encompasses both protocols that define the information space, by way
of identification and representation, and protocols that define the interaction of agents
within the Web. We further explore these three dimensions of Web architecture:
• Identification: Each Web resource is identified by a URI. A URI should be assigned
to each resource that is intended to be identified, shared, or described by reference
(linked). The fragment identifier of a URI allows indirect identification of a
secondary resource by reference to a primary resource and additional information.
URI is used to access a resource. Access may take many forms, including retrieving
a representation (e.g., using HTTP GET or HEAD), modifying the state of the
resource (e.g., using HTTP POST or PUT), and deleting the resource (e.g., using
HTTPDELETE).
• Interaction: Web agents exchange information via messages that are constructed
according to a non-exclusive set of messaging protocols (e.g., HTTP, FTP, NNTP,
SMTP, etc.). These messages arise as the result of actions requested by a user or
called for by a rendering engine while processing hypermedia-aware data formats.
A message consists of representation data and possibly resource metadata (e.g.,
HTTP ‘alternates’ and ‘vary’ headers), representation metadata (e.g., HTTP
content-Type field), and/or message metadata (e.g., the HTTP transfer-encoding
header).
• Representation: Messages carry representations of a resource. A resource com-
municates the overall information about its state through these representations,
Provide information
(data)
read / write
Application
Data
Programs
User Interface
Provide functionality
(services)
Manipulate
data
Figure 2. Basic terms relations

Another Random Scribd Document
with Unrelated Content

"Ah, but if it isn't?" said Amanda, in her impressive whisper, which
seemed fraught with a mysterious consciousness of power.
Another silence. The defiant look on Elizabeth's face faded; she
leaned back in her chair and half closed her eyes. Ah, she was
weary, deathly weary, of these constant nervous shocks. How much
did Amanda know—how much? If she could only be sure!
"I think they'd be rather surprised," Amanda went on, in unnaturally
quiet tones, "these swell friends of yours, if they knew all about you.
They think you very sweet, they give you lots of things"—Amanda's
hard, restless eyes roamed again about the room and rested on
Elizabeth's beautiful gown. "It don't seem fair," she broke out,
suddenly, with a fierce little sob; "it don't seem fair, that you should
have so much—and then to be so pretty too, as well as all the rest!"
She was silent for a moment, struggling with the tears that
threatened to break forth, and Elizabeth began to breathe more
freely. All this bluster, after all, these vague threats, seemed to
resolve themselves into the old, unreasoning, powerless jealousy—
nothing more. And with the relief came again the sense of pity, of a
certain justice in Amanda's point of view.
"It isn't fair," she said, softly. "I don't deserve it, but"——
"Well, fair or not, I guess it don't make much difference," Amanda
interrupted her, drearily, rising to her feet. "You've always had the
best of me, and probably, you always will. But, if ever you don't"——
She broke off suddenly and moved towards the door. "I guess I'd
better be going," she said. "You'll be late for your dinner. Only,
before you go"—she paused with her hand on the knob of the door,
that hard, mocking glitter in her eyes—"before you go, just put on
some of your jewelry, won't you? Seems to me you look sort of bare
without it."
"My—my jewelry?" Elizabeth's heart, which had been beating more
quietly, suddenly stood still. "I—I don't wear jewelry, Amanda," she
said, in a dull, toneless voice.

"What, not your pearls?" Amanda's hard, mocking eyes seemed to
read her through and through. "Your pearls you were so proud of in
the country, that you said you'd always wear. Seems to me you need
them—with that fine dress!"
She stood hovering by the door, a weird figure in the exaggerated
smartness of her attire, with her white face framed in the deep red
hair, and that strange, uncanny smile gleaming across it, lighting it
up into an elf-like suggestion of mysterious power. Elizabeth stared
at her helplessly, fascinated; then, with a great effort, she roused
herself and hurried towards her.
"Amanda!" she cried, desperately. "Amanda, for Heaven's sake, stop
these insinuations! Tell me plainly what you mean?" She gripped her
fiercely by the arm, her face was white and set. For a moment
Amanda's eyes met hers. Then, as if in spite of herself, they fell, she
freed herself sullenly from Elizabeth's grasp.
"Well, I guess I didn't mean much," she said, awkwardly, "or if I did,
it don't matter. I wouldn't tell tales against—my first cousin"—She
turned the knob of the door, but again she paused, that weird smile
still flickering in her eyes. "Good-night," she said, "I hope you'll
enjoy your dinner. Too bad you haven't got your pearls." She gave
one last jarring laugh, opened the door and went out.
Elizabeth, white and trembling, sank into the nearest chair.
"How she frightened me!" she gasped out. "These constant shocks
will kill me. Does she know anything definite? Probably not. But what
can I do, how can I find out?—Ah, Celeste!"—as the maid appeared
with an anxious expression in the door-way. "The carriage is waiting?
Very well." She hurried to the dressing-table, caught up her gloves
and gave one hasty glance at her white face. "How ugly I am
growing," she thought, turning away with a shudder; "quite like
Amanda! I see the resemblance. It is this awful life. I wish—oh, how
I wish I were home!" The thought swept over her, thrilling her with

an intense, passionate longing for her aunts' presence, for the
country quiet, for rest and peace.
"Yes, I will go home," she thought, as Celeste adjusted the cloak
about her shoulders and she hastened down to the carriage. "I will
go home," she repeated to herself at intervals during the evening,
while she talked and laughed with a restless light in her eyes and a
feverish flush on her cheeks. "The country will be so peaceful. I shall
be quite safe there, away from all this agitation, this trying to keep
up appearances. It is the best way out. How fortunate that he is
away! I won't see him again before I go."
It was, she felt, an heroic resolution. Yes, she would go at once. And
she resolutely crushed back the thought: "He will follow."

"T
Chapter XXV
he Van Antwerps have come up for the summer," said Miss
Joanna, who had made the same announcement, if you
remember, not quite a year before. "The butcher says they came last
night. They never got here so early before."
Elizabeth, who was arranging flowers, looked up suddenly. "Yes, I
know," she said, quietly, "Eleanor wrote me." She left her roses half
arranged, and wandered restlessly over to the long French window.
Before her stretched the well-kept lawn, with its flower-beds and
rose-bushes and beyond, field and wooded upland, all clothed in
their newest, most vivid dress of green; further still the river, with
the white sails on its surface—that river from which, more than half
a century before, another Elizabeth Van Vorst had resolutely turned
away her eyes, refusing to be reminded of the life that she had
given up. But that woman of an older generation was made of
sterner stuff, perhaps, than her grand-daughter. And then there was
not much travel in those days, no daily mails, no guests coming up
to neighboring house-parties over Sunday.... "It will be nice for you,
Elizabeth, to have Mrs. Bobby," said Aunt Joanna, in her comfortable
monotone, her knitting-needles clicking peacefully. "You have found
it a little dull, you know, dear, since you came back."
A little dull! Elizabeth could have laughed out loud at the words. A
little dull—with such exciting subjects to discuss as the new Easter
anthem, and the latest illness of the Rectory children; with such
diversions as a drive to Bassett Mills, a tea-party at the Courtenays!
...
"If I am dull," she said, turning round presently with the ghost of a
smile "It certainly isn't the fault of the Neighborhood. I didn't tell you

that Mrs. Courtenay has asked me to tea—a third time. She says
'Frank will see me home—no need to send the carriage.'" She
laughed a little, not without a shade of bitterness. "Fancy Mrs.
Courtenay suggesting that—last summer!"
"Well, dear, she means well, I suppose," said Miss Joanna, puzzled
but kindly. Miss Cornelia raised her head with a little, involuntary
touch of pride.
"The Courtenays are—are really quite pushing, I think," she said, a
most unwonted tone of asperity in her voice. "I told Mrs. Courtenay,
Elizabeth, that you had been so very gay"—with emphasis—"you
really needed a complete rest."
Elizabeth laughed. "And of course," she said "that only made her—
dear good woman!—all the more anxious to provide me with a little
more amusement. I never realized before how fond the girls have
always been of me. But then that's the case, apparently with the
whole Neighborhood. They always concealed their affection for me
very successfully—until this spring!"
She paused, her aunts made no reply. She went over to the piano
and began absently turning over sheets of music.
"Do you remember, auntie," she said, abruptly—Miss Joanna had left
the room in response to a summons from the maid, and Elizabeth
and Miss Cornelia were alone—"do you remember that I told you
once that I felt myself a sort of nondescript—neither flesh, fowl, nor
good red herring? But now I seem to be considered a very fine fowl
indeed—the ugly duckling, probably, that turned into a swan."
"You never were an ugly duckling, my dear," Miss Cornelia could not
help protesting, in spite of her principles. "It certainly wasn't that."
"Perhaps not," said Elizabeth, "at all events, I'm no better-looking
than I was—let us say, last year. I heard a woman at The Mills say
the other day that I had "gone off terrible," in my looks. But that
doesn't prevent Frank Courtenay from coming here day after day,

boring me to death, since he has discovered as his mother tells me,
that I am "just the style that he admires"—it doesn't prevent the
Johnston girls from going into raptures over my beautiful hair, and
asking if I mind their copying my lovely gowns. They have copied my
new spring hat, if you notice. Oh, it would be amusing, if it wasn't—
so very petty!" She put out her hand with a weary, contemptuous
gesture. "And then the funny part of it all is that I am not really so
nice, if they only knew it, as I was last year, when they all treated
me as if I had committed some sort of crime, merely in existing."
"My dear," remonstrated Miss Cornelia, "how can you talk like that?
I'm sure you're not a bit spoiled—every one says so."
"Ah, they think so," said Elizabeth, quickly, "they think me nice,
because I've acquired a society manner, and say the correct thing,
but if they knew—everything"—she stopped suddenly and stood for
a moment staring steadily before her, with knit brows. "Do you
know, Aunt Cornelia," she said abruptly "what I think I am?—a sort
of moral nondescript, neither good nor bad. I see the right way—oh,
I see it so very plainly, and I want to take it; and then I choose the
wrong—always and inevitably I choose the wrong, and shall all my
life, until the end. It's not my fault, really—I can't do right, no matter
how hard I try."
"My dear!" Miss Cornelia looked at her, puzzled and shocked.
"There's no one," she said, putting into trite words her own simple
conviction "there's no one, Elizabeth, who can't do right, if they try
hard enough."
"Do you think so, auntie?" said Elizabeth, very gently. "Then
probably I don't try—hard enough." She went over to Miss Cornelia
and kissed her on the cheek. "If I were like you," she said, "I
should." Then without further words, she sat down at the piano and
began to play, as she did every day for hours at a time. Such
restless, passionate, brilliant playing! A vague uneasiness mingled in
Miss Cornelia's mind with her pride in the girl's talent, as she listened
to it. Something was troubling Elizabeth, evidently; something which

had brought her home so unexpectedly, which had changed her in
looks and manner beyond what could be accounted for by
excitement and late hours. Yet innate delicacy and timidity
prevented Miss Cornelia from forcing in any way the confidence
which seemed to tremble, now and again, upon the girl's lips. She
had a vague idea that the difficulty, whatever it was, would soon be
decided one way or another, that the Van Antwerps' arrival, which
Elizabeth seemed at once to dread and look forward to, would bring
matters to a crisis, and the whole thing would be explained.
Elizabeth was still playing when Mrs. Bobby interrupted her. That she
had not allowed a day to elapse before hastening to the Homestead
was a fact noted with jealous care by the Misses Courtenay, who
met her at the gate.
"He is desperate." Mrs. Bobby's visit had not lasted many minutes
before she murmured this, holding Elizabeth's hand, and scanning
eagerly her averted face. At Mrs. Bobby's words it quivered, the
color flushed into her cheek; but otherwise she made no sign.
"When you first went away," Mrs. Bobby continued, as no answer
came, "he was all for coming up here at once. He thought it a
caprice, a morbid, unaccountable whim; he was sure that if he could
see you, remonstrate with you—And then there was your letter,
forbidding him to come. He was beside himself! It was all I could do
to keep him from taking the first train up here. I said—Wait—it
doesn't do, always, to force a woman's will; give her a little time. At
least she has paid you the compliment, which she has paid to no
one else of—running away from your attentions."
She paused, her eyes still eagerly fixed upon Elizabeth's face. The
color in the girl's cheek was now brilliant, her lips were parted; but
still she did not speak.
"Day after day," said Mrs. Bobby, "we have talked it over—he
walking up and down, restless, wild; I trying to soothe him, urging
him to be patient—Sometimes he thinks that you are revenging

yourself in this way for his former neglect, that it is a little scheme to
pay him back—the idea drives him frantic, makes him furious with
himself, yet he is always encouraged when he thinks of it. And then
again—he thinks that you don't care for him, that you never will,
that there is some one else.... Ah, my dear, if you really do care, you
are cruel, unpardonably cruel, to torment him like this."
Again she paused. Elizabeth, with a quick, impatient movement,
dragged her hand away from her grasp, and began to pace up and
down, gasping as if for breath. "Cruel," she cried out, "cruel! And
you think it gives me pleasure—to torment him!"
"If it doesn't," said Mrs. Bobby, following her with her eyes and
speaking with some coldness, "I confess I am at a loss to account
for your behavior."
Elizabeth stopped suddenly and bending down, almost buried her
face in the roses, whose fragrance she inhaled.
"There never was a man," said Mrs. Bobby, "who loved a woman
more than he loves you, Elizabeth. And there isn't a man, who, I
believe, deserves a woman better."
"Deserves her!" murmured Elizabeth, "deserves me! Oh, good
Heavens!" The exclamation was barely audible, and apparently
addressed only to the roses.
"I said to him yesterday," said Mrs. Bobby, "'You'll come up Saturday,
of course?' But—he's proud now and hurt, Elizabeth—he said: 'I
won't come, I won't force myself upon her without—her knowledge
and consent. If she knows, if she's willing, why, then, I'll come—not
otherwise.'"
There was a pause. Elizabeth turned presently a face which seemed
to reflect the glowing color of the roses over which she had bent.
"What do you—want me to do, Eleanor?" she asked, softly.
"Tell me what I shall say," said Mrs. Bobby "in the letter which I
must write when I get home." She went over to Elizabeth and put

her hand on her arm. "Shall he come, or shall he not? It rests with
you."
Elizabeth's eyes were again averted. "It isn't for me, Eleanor," she
murmured, "to drive your guests away, if—if they really want to
come."
And so Mrs. Bobby, when she got home, wrote her letter. It
consisted of only one word.
The Saturday following was extremely warm. The Rector and his
wife came to take tea at the Homestead, and they all sat afterwards
in the dimly-lighted drawing-room. Elizabeth wandered to the long
French window, and stood looking out upon the moon-lit lawn. "It's
so warm that I think I shall go for a walk," she said, half aloud, but
no one heard her. The Rector was telling Miss Cornelia about the
death of an old clergyman in Cranston, who had lived alone with two
old servants. Elizabeth stood and listened for a moment to the deep,
impressive tones which mingled strangely with the comfortable
monotone which the Rector's wife was addressing to Miss Joanna.
"And so," she was saying "you see I have had blue put on it again,
being more summery"—
"I feel particularly sorry," the Rector's voice broke in, "for the old
servants. They were quite prostrated, I fear, poor things! They too
have not long to live."
"Black satin at four dollars a yard," said his wife, "is sure to last
forever."
"He was an excellent man," said the Rector. "His death is a great
loss." But here Elizabeth, weary of listening, softly turned the knob
of the window and stepped out on the lawn.
What a beautiful night it was outside! The long twilight was fading
into dusk, but the moon silvered the shadows that the trees cast
across the road. Elizabeth walked to the gate and stood leaning
against it. In the distance she heard distinctly the sound of a horse's

hoofs. It grew nearer and nearer, and in a few moments a man on
horseback was beside her, and drew his rein abruptly before this
figure in white, which stood like an apparition in his path.
"Elizabeth," he said. "Elizabeth, is it you?"
"Did you think it was my ghost?" she asked, with a soft laugh. Her
white gown shimmered in the moonlight, her hair framed in her face
with a vivid halo, her eyes shone like stars. Gerard sprang from his
horse.
"Elizabeth," he said "were you waiting for me?"
"Yes," she answered, "I was waiting for you."
And the next moment he had her in his arms, and she had forgotten
all other thoughts, all other claims, beneath the fervor of his kisses.

T
Chapter XXVI
he summer passed for an eventful one at Bassett Mills, being
marked by at least two subjects of conversation; the one the
engagement of Elizabeth Van Vorst of the Homestead "that girl of
Malvina Jones," to a gentleman from town, who was reported to be
"rolling in wealth;" the second, the illness of Amanda Jones, of that
fashionable disease called nervous prostration, which no other girl at
Bassett Mills but Amanda, who had always given herself airs, would
have had the time or the money to indulge in. She had been taken ill
while visiting her relations in New York, and her mother had gone up
to nurse her, and announced on her return that Amanda was "that
nervous" the doctor—"the best that could be had," as she observed
with pride, had recommended complete rest, and sending her to a
sanitarium for a few months.
"But there really ain't much the matter with her," Amanda's mother
explained rather tartly to Elizabeth, who inquired for particulars as to
her cousin's illness. "She has fits of crying, and then of sitting still
and staring straight before her, like as if she was in a trance, and
then she'll get up, and walk up and down the room for hours, and
sometimes she'll notice you, and sometimes she won't—but dear
me, it's all nonsense, I say. If she had some hard work to do, it
would be better for her—but the doctor didn't seem to think so, and
so I let her go to the sanitarium. No one shall say that I grudge the
expense, as, thank Heaven! I don't have to, though there ain't
another person at The Mills that wouldn't."
"I'm sure I hope it will do her good," Elizabeth said, kindly. She felt
so glad to have Amanda, whatever the reason, away from Bassett
Mills that she was conscious of a sudden pang of remorse, which
increased when she received a letter from her cousin, congratulating

her upon her engagement. It was a perfectly rational letter, with only
slight references to her illness, and none at all to that unpleasant
last interview in town; and Elizabeth answered the congratulations in
the same amicable spirit in which they were offered, reflecting that,
after all, much of Amanda's peculiarity must be excused on the
ground of her persistent ill-health. And yet, as she sealed and
directed her own letter, she breathed again a fervent thanksgiving
that Amanda was safely out of the way.
There was another person for whose absence just then she felt
devoutly thankful. When her engagement was announced, early in
July—against her own wishes and in deference to Gerard's—she had
received a terrible letter from Halleck, denouncing her perfidy, and
threatening to come up at once. She had answered it as best she
could, imploring his silence, and enclosing a sum of money which
she borrowed from her aunts, on the plea of urgent bills—far from
mythical, unfortunately, but which remained unpaid. Whether or no
Paul granted her request, he pocketed the money, and she next
heard of him as having gone abroad for the summer. The piece of
news, casually mentioned one day in the course of conversation,
thrilled her with a sense of overpowering relief, a suggestion, against
which she struggled in vain, of possible accidents, of all the things
that might reasonably happen to those who travel by sea or land.
Elizabeth breathed a devout wish—it might almost be called a prayer
—that this particular traveler might never return.
Meanwhile, the summer passed; a cool, delightful summer, rich with
a succession of fragrant, sunshiny days and long, balmy evenings;
and signalized by what for the Neighborhood was an unusual
amount of gaiety. Several entertainments were given in honor of
Elizabeth's engagement, among others a large dinner at the Van
Antwerps'. And for this Elizabeth wore—it was Gerard's fancy—the
same white gown in which he had first seen her, which he vowed
that he cared for more than all her other gowns put together. And
though she had pouted a little and declared that the others were far
more smart, she yielded to his wishes in this, as she did in most

things. Yet during the evening she noticed now and again his eyes
fixed upon her with an odd, doubtful expression, as one who
searches his memory for the details of a likeness, and finds
inexplicably something lacking.
"I know what it is," he announced, abruptly, when they had
wandered after dinner for a little while into the conservatory. "I was
wondering what it was I missed, and now I know. You haven't got
on your pearls. You wore them that night—in fact, I never saw you
in full dress without them."
She flushed beneath his wondering gaze, reflecting how constantly
he had observed her, wishing—almost—that he had not observed her
quite so much.
"Did you forget them?" he asked smiling, as she made no response,
but merely put up her hand to her white neck, as if just reminded of
the fact that it was unadorned.
She plucked a rose from a plant near by, and began, nonchalantly, to
pull it to pieces.
"Oh, I—I didn't feel in the mood to put them on," she said carelessly.
"I—somehow I think I shall not be in the mood to wear them again
for a long while."
He was watching her lazily, an amused smile gleaming in the depths
of his dark eyes. "What an odd, capricious child you are!" he said.
"You're all made up of moods. I never know what to expect next."
She was picking the rose to pieces very deliberately, petal by petal,
her eyes cast down. "Yes, I'm all made up of moods," she echoed,
softly. "You must never be surprised at anything I do or say."
"I'm not," he returned, smiling. "And yet," he went on, after a
moment, "I confess I'm a little surprised—and disappointed at this
last one. I was thinking, to tell the truth, as I had an idea you valued
those pearls particularly, of asking you to let me have them, so that
I could get you another string to match them exactly."

The last petal of the rose fell from Elizabeth's hand, she stared up at
Gerard with an odd, frightened expression. "Don't," she broke out,
harshly. "I—I hate pearls." Then with a sudden change, as she saw
the absolute bewilderment in his face, she laid her hand gently on
his arm. "Dear," she said, very sweetly, "you must have patience
with my moods. I've got an idea, just now, that pearls are unlucky.
It's very silly, I know, but—don't argue with me. Bear with me,
Julian, let me have my own way—a little."
They were alone in the conservatory. He put his arm around her and
pressed his lips to hers. "A little," he murmured. "Have your own
way—a little! Didn't I tell you, my darling, that you should have your
own way in everything?"
She seemed to shrink away with an involuntary shiver at the words.
"Ah, but I don't want it," she protested. "It's the last thing I want.
If"—she freed herself from his hold and stood looking him, very
sweetly and steadily, in the face—"if we are married, Julian"—
"If!" he echoed, reproachfully.
"It's always safer to say 'if'" she said.
"Ah, but that's a suggestion I won't tolerate," he declared, firmly. "I'll
have my own way in that, if in nothing else. But, when we are
married, Elizabeth"—he paused.
"When we are married, then,"—she ceded the point resignedly,
blushing rosy red—"when we are married, Julian, it must be your
way, not mine. Yours is far better, wiser—yes"—she stopped his
protest with an imperious gesture—"I feel it, even though I try
sometimes to dispute it. I shall never do that—later. I shall try, with
all the strength I have, to be more worthy of your love. But now—
just now, Julian"—she looked at him anxiously, and a note of appeal
crept into her voice—"if I seem odd, wilful, don't blame me, don't—
doubt me"—

"Doubt you?" He took her hand and raised it reverently to his lips. "I
shall never doubt you—again, my darling, no matter what you do or
say."
There was the ring of absolute confidence in his voice. Yet it might
have been that which made her shiver and shrink away, almost as if
he had struck her a blow.
"I—I think we had better go back to the others," she announced,
abruptly, in a moment, and her intonation was quick and sharp,
almost as if she were frightened and trying to escape from some
threatened danger. "It"—she smiled uncertainly—"it's not quite good
form, I think, for us to wander off like this."
"Hang good form!" said Gerard, but still he followed her back
resignedly to the other room, and she gave, as they reached the
lights and the people, a soft sigh of relief, which fortunately he did
not hear. Yet he noticed that for the rest of the evening she was
paler than she had been at first.
This pallor increased when Mrs. Bobby, too, voiced the question
which had been perplexing her all the evening, as to why she did not
wear the pearls. Elizabeth did not mention her moods—it is evident
that women cannot be put off, in such important questions as that of
jewelry, with the vague answers that might satisfy a man. She said
that the string had broken, and she had sent them to town to be re-
strung. Her aunts knew that they had been there for that purpose
since early spring, and they could not understand why she did not
send for them, since other things had been left at the same jeweler's
—notably that little jeweled watch, which they had heard of, but
never seen. It was odd that Elizabeth should have lost, to so large
an extent, her taste for pretty things.
Gerard, too, noticed this, but he would not ask her any more
questions. Later he gave her a string of emeralds set with diamonds,
which she wore to entertainments in the Neighborhood that autumn,

and no one asked any more questions about the pearls, since it was
natural that she should prefer to wear his gift.
His trust in her was absolute, as he had said. It seemed as if he
would make amends now by the plenitude of his confidence, for that
former instinctive, reasonless distrust. And then she was so different
from the frivolous girl he had first imagined her. Every day he
reproached himself with his old estimate of her character, as he
discovered in her new and unexpected depths of brain and soul. She
read all the books that he recommended—some of them very deep,
and she would once have thought very tiresome—and she surprised
him by the intelligence of her criticisms, she took a sympathetic
interest in those articles by which he was making a name for himself
in the scientific world, and she entered with an apparently perfect
comprehension into all his hopes, thoughts and aspirations. There
was only one thing in which she baffled him, one point where her
old wilfulness would come between them. This was her obstinate
and unaccountable refusal to name their wedding day.
The Neighborhood was exercised on the subject. It had been
decided by unanimous consent that the wedding should be in the
autumn—"quite the best time for a wedding" as the Rector's wife
observed, and lay awake one whole night planning the most
charming (and inexpensive) decorations of autumn leaves and
golden-rod. But all the reward she received for her pains was the
information that Elizabeth did not care for autumn weddings, and as
the Misses Van Vorst at Gerard's request, had taken a small
apartment in town for the winter, the Rector's wife had many pangs
at the thought that the Bassett Mills church and her husband would
lose all the prestige that would attend this great event—to say
nothing of the fee.
But when Gerard, as a matter of course, spoke of their being
married in town, Elizabeth looked up deprecatingly into his face.
"Wait till I'm twenty-one," she pleaded. "This is my unlucky year, you
know. Do please, Julian, wait till it's over."

But Gerard's face was set in rigid lines, like that of a man who is
determined to stand no more trifling. Elizabeth's unlucky year would
not be past till April.

I
Chapter XXVII
t was a bleak December day and Central Park seemed the last
place where one would wish to loiter. The sky hung lowering
overhead, gray, cold, heavy with the weight of invisible snowflakes.
The wind made a dull moaning sound, as it stirred the bare branches
of the trees. The lake, where at another season you see children
sailing in the swan-boats, was nearly covered with a thin coating of
ice. But Elizabeth Van Vorst as she stood with eyes intently fixed
upon the small space of water still visible, did not seem to notice
either the cold or the dreariness of the scene. She was leaning
against a tree, and looking at nothing but the lake, till at the sound
of foot-steps on the path, she turned to face Paul Halleck.
"So you got my note," she said, speaking listlessly, without a sign of
surprise or satisfaction. She did not give him her hand, which
clasped the other tightly, in the warm shelter of her muff.
"Yes, I got it; but I could wish you had chosen a warmer meeting-
place, my dear." The last months had changed him, and not for the
better. His figure had grown stouter, his beauty coarser. She shrank
away in invincible repugnance from the careless familiarity of his
manner.
"It was the best place I could think of," she said, curtly. "At home,
we are always interrupted; at your studio—it is impossible. I had to
see you—somehow, somewhere." She sat down on a bench near by,
and shivering drew her furs about her.
"You do me too much honor," Paul returned, lightly. He took the seat
beside her, his eyes resting, in involuntary fascination, on the
rounded outlines of her cheek, the soft waves of auburn hair
beneath her small black hat. "It's a long time since you have wished

to see me of your own accord, my dear," he said, in a tone in which
resentment struggled with his old, instinctive admiration of her
beauty.
She turned to him, suddenly, her eyes hard, her face very white and
set. "You know the reason." "I had to see you, to—to talk things
over. You assume a right to control me, you ask me for money, you
try to frighten me with threats. There must be an end of it. I"—she
paused for a moment, and drew her breath quickly, while she
flushed a dull crimson. "I have promised—Mr. Gerard," she said "to—
to marry him next month."
He interrupted her with a scornful laugh. "To marry him—next
month," he repeated. "And how about that ceremony which we
know of—you and I—in the church at Cranston?"
The crimson flush faded and left her white, but still she did not
flinch. "I have thought of that," she said, steadily, "and I have
decided that it should not—make any difference. I don't believe the
marriage would be legal—but that's neither here nor there. I don't
want a divorce, I don't want the thing known, I don't consider that
we were ever married. I don't think such a marriage as ours, which
we both entered into without the slightest thought, which we have
repented of"—
"Speak for yourself," he interposed.
"Which I have repented of, then," she went on, "ought to be
binding. The clergyman who married us is dead; the witnesses, so
old that they are childish, probably remember nothing about it.
There is no one now living who remembers, except you and I. And
for me I have determined to think of it as a dream, and I want you
to promise me to do the same."
"But—there is the notice in the parish register." He was staring at
her blankly, admiring in spite of himself, the calm resolution of her
manner, the business-like precision with which she was unfolding her
arguments, as if she had rehearsed them many times to herself.

"I have thought of that, too," she said, in answer to his last
objection, "and I don't think it in the least likely that any one will
ever see it. Why should they, without any clue? At all events, this is
—the only way out." She faltered as her mind wandered for a
moment unwillingly to another way which she had now despaired of
—too easy a solution to her difficulties ever to come true. What a
fool she had been to think that he would die! People like that never
die. As she saw him now, in the full pride of his health and good
looks, it seemed impossible to believe that any misfortune could
assail him—least of all death! ...
"There is—no other way," she repeated, with a little, involuntary sob.
"The risks are not great—but, at any rate, I must take them. Now,
there is only one other thing"—She paused for a moment and then
drew out of her purse a plain gold ring, and showed it to him. It was
the ring which she had once worn on her finger for a few minutes,
which she had kept carefully hidden ever since. She glanced about
her; there was no one in sight except the policeman, who in the
distance near the carriage-drive, was pacing up and down at his cold
post and beating his hands to keep them warm. Elizabeth rose and
went to the edge of the lake. With well-directed aim, she threw the
tiny circlet of gold so that it struck the fast-vanishing surface of
water and quickly disappeared. She drew a long sigh of relief.
"There," she said, "that is over."
Paul watched her curiously. He saw that she attached to this little
action a mysterious significance. He sneered harshly. "Very pretty
and theatrical," he said. "But do you really think that by a thing like
that—throwing away a ring—you can dissolve a marriage?"
She turned to him, her white face still resolute and intensely solemn.
"I don't know," she said, quietly, "but I wanted to throw it away
before you, so that you would understand that everything is over
between us, and that day at Cranston is as if it never had been.
Never had been, you understand," she repeated, with eager
emphasis. "I want you to promise to think of it like that."

He shrugged his shoulders. "How we either of us think of it, I
suppose, doesn't make much difference so far as the legality of the
thing goes," he said. "But,—have your own way. If you choose to
commit a crime, it's not my affair."
"A crime!" She started and stared at him. "Do you call that a crime?"
He smiled. "It's a rough word to use for the actions of a charming
young girl," he said "but I'm afraid that the law might look at it in
that light."
Elizabeth returned to the bench and sat down. She seemed to be
pondering this new view of the matter. "I can't help it," she said at
last, in a low voice. "If that's a crime, why—I understand how people
are led into them. And I can't ruin his happiness, crime or no crime."
"And my happiness?" he asked her bitterly. "You never think of that?
You professed to love me once. You took me for better, for worse,
and how have you kept your word? If my life is ruined, the
responsibility is yours. If you had gone with me as I wanted you to, I
should have been a different man." There was a curious accent of
sincerity in his voice. He really believed for the moment what he
said.
The reproach was not without effect. She looked at him more gently,
with troubled eyes that seemed to express not only contrition, but a
certain involuntary sympathy. "It's true," she said. "I have treated
you badly, and broken the most solemn promise any one could
make. I don't defend myself; but—I'm willing to make what amends
I can. I can't give you myself, but at least I can give you what little
money you would have had with me. When I am married to"—she
paused and flushed, but concluded her sentence firmly—"to Mr.
Gerard, I will give you—all the money I have."
Paul paced up and down, apparently in deep thought. It was evident
that her offer tempted him, yet some impulse urged him to refuse it.
He stopped suddenly in front of her. "Principal or interest, do you

mean?" he asked, in a tone in which the thirst for gain distinctly
predominated.
The doubtful sympathy in Elizabeth's eyes faded, and was replaced
by a look of unmistakable disgust. "I suppose I could hardly give you
the principal," she said, coldly. "But I will pay over the income every
year." She named the sum. "Isn't it enough?"
"That depends," he said, looking at her coolly. "It is enough, of
course, for Elizabeth Van Vorst, but for Mrs. Julian Gerard"—
He stopped as an electric shock of anger seemed to thrill Elizabeth
from head to foot. "You don't suppose," she cried, "that I would give
you his money?"
"Then," said Paul, curtly, "he doesn't know?"
"Certainly not," she said, haughtily.
He began again reflectively to pace up and down. "I don't see," he
said, "how you are to pay me over this money without his knowing
it."
"Don't trouble yourself about that," said Elizabeth, contemptuously.
"Mr. Gerard will never ask what I do with my money."
"Well he has enough of his own, certainly," said Paul, philosophically.
"And yet, poor fellow, I am sorry for him if he ever finds out how
you have deceived him."
"He never shall find out," said Elizabeth. She rose and pulled down
her veil. "It is so cold," she said shivering, and indeed she looked
chilled to the core. "I cannot stay here any longer. This thing is
settled, isn't it? You will promise?" There was a tone of piteous
entreaty in her voice.
"How am I to know," he asked, still hesitating "that you will keep
your word? Once married to Gerard, you might—forget."

"If I do," she returned quietly, "you will always have the power to
break yours and ruin my happiness."
"So be it, then. I won't interfere with you. After all, we probably
shouldn't have got on well. Come—let us part friends, at least."
He held out his hand, but hers was again securely hidden in her
muff, and the smile that gleamed on her face was pale and cold as
the winter day itself. "Good-bye," she said, and turned away. He fell
back, with a muttered oath.
"Upon my word, my lady," he said, "you might be a little more
gracious." At that moment Elizabeth came back. There was a softer
look on her face.
"I loved you once," she said. "Good-bye." And she held out her
hand. He took it in silence. Thus they parted for the last time.
It had been a successful interview. She had gained all that she dared
hope for. Seated in the warm car going home, and shivering as from
an ague, she told herself that she had silenced forever all opposition
to her wishes. Yet it did not seem a victory. Words which Paul had
said lingered in her mind, stinging her with their contempt, the fact
that even he could set himself above her. "A crime!" She had never
considered it in that light. Surely it was impossible on the face of it
that she, Elizabeth Van Vorst, could commit a crime.... And then
again—what was it he had said? "Poor fellow, I am sorry for him, if
ever he finds out how you have deceived him."
"But he never shall," she said to herself, resolutely as before. "Crime
or no crime, his love is worth it. He never shall find out."

E
Chapter XXVIII
lizabeth had little time in those days for thought. There was still
less time, even, when she was alone with Gerard. The days
passed in a whirl of gaiety, in which she had been swallowed up
since her return to town. It was a state of things which bored Gerard
extremely, but secure in the promise he had at last obtained from
her that the wedding should be at the end of January he possessed
his soul in such patience as he could muster. And when he requested
as a special favor, that she would refuse all invitations for the thirty-
first of December and see the Old Year out in peace, she consented
at once, and the hope of a quiet evening buoyed him up through
other weary ones, when he would lean in his old fashion against the
wall, and watch her across a ball-room, the center of an admiring
court. Yet, even as he did so, the proud consciousness of
proprietorship swelled his heart. She was his—his! He had no longer
any doubt of her, or jealousy of the men who talked to her.
Why then was the expected evening, when it came, fraught with an
intangible sense of gloom, of oppression, which made the time pass
heavily? The old Dutch clock, which the Misses Van Vorst had
brought with them from the country seemed to-night to mark the
hours with extraordinary slowness, as if the Old Year were in no
hurry to be gone, even though the noises in the street, the blowing
of horns and of whistles were enough, one might have thought, to
hasten his departure.
Elizabeth was pacing restlessly up and down the room. Her hands
were clasped carelessly before her, her long house-dress of white
cashmere, belted in by a gold girdle, fell about her in graceful folds.
There was a flush in her cheeks, a somewhat feverish light in her

eyes; she started nervously now and then as some enterprising
small boy blew an especially shrill blast on his horn.
"I don't know why it is," she said at last with a petulant little laugh,
coming back to her seat by the fire opposite Gerard, and taking up a
piece of work, in which she absently set a few stitches, "New Year's
Eve always gets on my nerves, I think of all my sins—and that's very
unpleasant!" She broke off, pouting childishly, as if in disgust at the
intrusion of unwelcome ideas.
He was watching her lazily, with the amused, indulgent smile which
certain of her moods had always the power to call forth; the smile of
a strong man, who felt himself quite able to cope with them. "With
such terrible sins as yours, Elizabeth," he said, "it must be indeed a
dreadful thing to think of them."
She turned quickly towards him. "You don't think that they can be
very bad?"
"I should be willing to take the risk of offering you absolution."
She bent down over her work so that her face was hidden. "Ah, you
—you don't know"——she rather breathed than spoke. He only
smiled incredulously, as one who knew her better than she did
herself.
"Play for me, darling," he said, after awhile, and she went
mechanically to the piano. But her playing was always a matter of
mood, and to-night her fingers faltered, the keys did not respond as
usual. She passed restlessly from one thing to another—snatches of
Brahms, Chopin, Tschaikowski, with the same jarring note running
through them all.
She broke off at last, with a wild clash of chords. "I can't play to-
night," she said, and came back to the fire. "How calm you are!" she
said, standing beside Gerard and looking down at him with eyes
almost of reproach. "This horrible evening doesn't get on your
nerves at all."

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