Michael Bolton - Two Futures of Software Testing

Two Futures of Software Testing
Michael Bolton
DevelopSense
EuroSTAR
November, 2008

Who I Am
Michael Bolton
(not the singer, not the guy in Office Space)
DevelopSense, Toronto, Canada
mb@developsense.com
+1 (416) 992-8378
http://www.developsense.com

Acknowledgements
 James Bach
− some of the material comes from the Rapid
Software Testing Course, of which James is the
senior author and I am co-author
 Cem Kaner
 Bret Pettichord
 Jerry Weinberg
 Richard Feynman

Ground Rules
 There are many strong opinions expressed in
this presentation
 You are welcome and encouraged to
challenge and debate them at any time
− you can share them, too, of course
 It’s up to you to decide whether to apply these
ideas in your context
− don’t let anyone (other than, perhaps, your boss) tell you
what to do

What is Testing?
 Testing is
 questioning
 the product
 in order to evaluate it
--- James Bach
This is the operational definition that we use
when we’re talking amongst skilled testers.

What is Testing?
 Testing is a process of
 empirical
 technical
 investigation
 done on behalf of stakeholders
 with the intention of revealing
 quality-related information
 of the kind that they seek
This is the definition that we use when we’re
trying to emphasize that testers need skills.
--- Cem Kaner
These definitions are not intended to disagree.

The Four Schools of Testing
 Bret Pettichord, The Four Schools of Software
Testing. Presentation at the Workshop on Teaching
Software Testing, Melbourne, FL, 2003.
− http://www.testingeducation.org/conference/wtst_pettichord_FSofST2.pdf
 This was an important attempt to understand testing
cultures and communities and their principles
 It’s most useful when the communities are viewed
sympathetically

The Four Schools of Testing
 The Analytical or Mathematical School
− testing is fundamentally an analytical activity; programs can be proven
correct by flowcharts and formulae
 The Routine or Process School
− testing should be procedurally structured an repeatable, not dependent
upon individuals
 The Quality Control School
− testers are the owners of quality on the project
 The Context-Driven School
− testing must respond and adapt to context
− the other schools may have valuable things to teach us
− nothing will guarantee perfect testing

The Dark Future:
The Plan is Everything
 Testing shall be a rigorously planned and
controlled process
− all planning and tests prepared in advance
− we test only according to documented requirements
− all testing is verification testing
 All projects shall take two years (minimum) to
give us time to plan
 All requests for change politely refused

The Dark Future:
Change is Controlled
 Nothing is more important than following
our process strictly
− our clients will understand, of course
− if they have want to change the requirements, they
should have known that from the beginning
 By insisting that requirements don’t
change, we can eradicate project risk

The Dark Future:
Measurement
 We measure
− requirements scope by counting requirements
− developer output by counting lines of code
− complexity by counting code branches
− test coverage by counting test cases
− product quality by counting bugs
− the value of testers by counting bug reports

The Dark Future:
Putting The Testers In Charge
 Testers are the quality gatekeepers
 Testers refuse to test until they have been
supplied with complete, unambiguous, up-to-
date requirements documents
 Testers “sign off” on project readiness
 Testers can block releases

The Dark Future:
Promoting Orthodoxy
 Testers must be certified
 Testing doesn’t require skilled labour
 All testers have the same skills
 Testers must be isolated from developers
 All tests must be scripted
 Ad hoc testing is banned; variation suppressed
 Exploration and investigation are luxuries that
we cannot afford

The Dark Future:
Automation is King
 Humans are too fallible to detect defects
 By eliminating the human element, we
can eliminate variability and uncertainty
 Sure, automation takes time and effort to
prepare, therefore…
 …we must slow down development to let
testing (particularly automation) catch up

The Dark Future:
Pathologies
 Places knowledge and learning up front, at the
beginning of the project
− when we know the least about it!
 Thinking and learning through the project are ignored
 Treats testing as unskilled work
 Machines are trusted; human cognition is devalued
 Measurement is riddled with basic critical thinking
errors
− primarily reification error and rotten construct validity

The Dark Future:
Pathologies
 Testers implicitly run the project when it’s convenient
for management to let them
 Even though testers are essentially powerless, they do
get blamed for lapses
− even though bugs have been created by others
− even though bugs are hidden
 When testers fail, it’s because
− they should have better requirements,
− they should have told their bosses and developers what to do

The worst thing about
the dark future is…

The Bright Future:
Skill Is Central
 Tester skill is at the centre of testing
 Important skills include
− critical thinking – recognizing bias and thinking errors
− general systems thinking – coping with complexity
− context-driven thinking – coping with changing situations
− scientific thinking – designing and performing experiments
− cognitive skills – learning and using lots of observational modes
− writing, recording, and reporting
− diversification of skills and tactics
− rapid learning
− programming
− but not necessarily for all testers

What IS Quality?
 Value is what someone will do (or pay)
to have their requirements met
 Quality is necessarily subjective
 Decisions about quality are political
decisions
− who has the power and authority to make them?
Quality is value to some person.
---Jerry Weinberg

The Bright Future:
Testing is a Service
 Testing provides services for the rest of the project
community
 The primary role of testing is to provide quality-related
information to management
 Testers do excellent work
− with insufficient or barely sufficient information
− under extreme time pressure
− with the tools that are available (or that they develop quickly)
− in a way that stands up to scrutiny
− even when everyone else is breaking the rules
 Management makes management decisions

The Bright Future:
Information In Context
 Testers are expert communicators
 Testers identify and frame context
− to make sure that testing matches the mission
 Testers seek alternative test approaches, explanations,
and perspectives
− to reduce the possibility that we’ll miss important problems
 Testers are skeptical (but not cynical) empiricists
 Testers reject bogus metrics
− most metrics that we currently use in testing are bogus
− see Kaner and Bond, “Software Engineering Metrics: What Do They
Measure and How Do We Know?”

The Bright Future:
Test Activities
 Testers actively question the product in order to
evaluate it
 Testers focus on risk
 Testers continuously develop new questions
 Testing is investigative, as well as confirmatory
− as in the agile model, developers handle the bulk of the
confirmatory testing effort at the unit level…
− where automation is inexpensive and feedback is immediate
 Testers develop skill in exploratory testing
− parallel test design, test execution, and learning

The Bright Future:
Change Happens
 Testers expect and embrace change
 Confirmatory testing serves as a change detector
− We would love it if the developers embraced unit tests and TDD
− …because it would allow us to obtain greater coverage in less time
− …but ultimately that’s their business (and management’s), NOT ours
 Investigative testing changes rapidly depending on what is
being investigated and discovered, so test artifacts are
− lightweight, where appropriate
− efficient (leaving us more time to run tests)
− produced in service of a genuine purpose
− not clerical or bureaucratic
− not overinvested
− not wasteful

The Bright Future:
Machines Do Mechanical Work
 Automation assists the testing effort
− machines do high-speed, simple-oracle tasks
− people do high-skill, high-cognition tasks
 Testers do not work from scripts
− testers do excellent work with concise guidance
− where recording is important, keep records
 Testers work from far more than requirements
documents
− testers apply inference, conference, and reference heuristics
− testers are general-systems thinkers

The Bright Future:
Testers Collaborate
 Many (even most) testers are co-located with
developers
 Testers provide extremely rapid feedback
 Testers and developers collaborate on
testability
− controllability (scriptable interfaces, easy reconfiguration)
− visibility (on-screen status, log files)
 Many testers learn to program
− many, but not all
− most testers learn regular expressions and spreadsheet skills

The Bright Future:
Narratives vs. Numbers
 Testers compose, edit, and narrate cogent stories
− about the product
− how it can work
− how it might fail
− and about their testing
− what they did, and why
− what they didn’t do, and why
− and why the testing was good enough
 Test managers encourage management to reject
deceptive quantitative measures
− example: counting test cases
− example: counting bugs
 Testers don’t supply numbers without a story

The Bright Future:
Testers Focus on the Mission
 If the mission requires lots of documentation and
data, we supply it
− but we regularly check to make sure that it’s adding value
− I guarantee that someone will leave this presentation claiming that I
advocate no documentation, ever
− I don’t advocate that, and this is the documented proof
− I advocate no documentation that wastes time and effort
 If the mission requires lots of automated testing, we
develop it
− but we don’t stop brain-engaged exploratory tests
 If the mission requires us to suspend our skills, we do
− on the understanding that someone else is responsible for the quality of
our work

This is our role.
We see things for what they are.
We make informed decisions about quality possible,
because we think critically about software.
We let management make those decisions.
Testers Light The Way

We also think critically about our own work.
We question our context and our choices,
both of which evolve over time.
We question testing folklore.
Testing is NOT mythodology.
Testers Light The Way

Learning More:
Finding Bugs
 Lessons Learned in Software Testing
− by Cem Kaner, James Bach, and Bret Pettichord
 Testing Computer Software
− Cem Kaner, Jack Falk, and Hung Quoc Nguyen
 How to Break Software
− Whittaker
 How to Break Software Security
− Whittaker and Thompson
 Testing Applications on the Web
− Hung Quoc Nguyuen
 Hacking Web Applications Exposed
− Joel Scambray and Mike Shema

Learning More:
Testing Philosophy
 The Pleasure of Finding Things Out
− Richard Feynman. Read his Appendix to the Challenger Report.
 Surely You’re Joking, Dr. Feynman! Adventures of a
Curious Character
− Richard Feynman
 What Do You Care About What Other People Think?
− Richard Feynman
 Quality Software Management Vols. 1 – 4
− Jerry Weinberg
 Anything by Jerry Weinberg

Learning More:
Other Wonderful Stuff
• Please Understand Me
• David Kiersey
• The Myers-Briggs Type Inventory, which provides insight into your own
preferences and why other people seem to think so strangely
• The Visual Display of Quantitative Information
• Edward Tufte
• How to present information in persuasive, compelling, and beautiful ways
• A Pattern Language
• Christopher Alexander et. al
• A book about architecture
• even more interesting as a book about thinking and creating similar but unique
things—like computer programs and tests for them
• Better Software
• a most unfortunate name of a most wonderful magazine
• The Amplifying Your Effectiveness Conference
• held every November in Phoenix, AZ
• See http://www.ayeconference.com for details

Learning More:
On the Net
• StickyMinds http://www.StickyMinds.com
• Risks Digest http://catless.ncl.ac.uk/risks
• Cem Kaner http://www.kaner.com
• James Bach http://www.satisfice.com
• Michael Bolton http://www.developsense.com
• The Florida Institute of Technology
• http://www.testingeducation.org
• http://www.testingeducation.org/BBST/index.html

Michael Bolton - Two Futures of Software Testing

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