Human Computer Interaction
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This document discusses various aspects of human-computer interaction (HCI) and user interface design. It begins by defining HCI and its goals of making systems useful, usable and satisfying to users. It then discusses why good UI design is important, covering both explicit and implicit forms of interaction. The document outlines challenges in areas like ubiquitous access and personalized spaces. It analyzes interfaces for different devices like PCs, mobile phones, games consoles and remote controls. It also covers multimodal interaction, gestures, wearable and implanted devices. Finally, it briefly introduces the human-centered design process.
Human Computer Interaction
- 1. Bhakti Patil Assistant Professor, AISSMS College of Engineering
- 2. Introduction HCI used to empower people to cooperate with different devices. To perform tasks and support activities efficiently. Designed to be useful and to be helpful to be usable. Human: users of system, single or many, having diverse abilities. Computer: not only PCs but also different devices. Interaction: commands to handle imaginary objects.
- 3. Why it is needed? Poor UI can lead to higher training costs, higher usage cost, Ultimately it will lead to low sales of the product. Poor UI may also lead to higher error rates (not acceptable in critical systems). Based on the user experience success is dependant.
- 4. Explicit HCI User is always at the center of interaction. System control responds to and generated by human System is not driven internally but by user. Complex to coordinate lot of inputs by different devices to perform concurrent activities.
- 5. HCI motivation To support more effective use. useful: accomplish a user task that the user requires to be done usable: do the task easily, naturally, safely (without danger of error) used: enrich the user experience by making it attractive, engaging, fun, etc. The success of a product depends largely on both the user’s experience with how usable a product is and how useful it is in terms of the value it brings to them.
- 6. Haeckel’s law and inverse law Heckel’s law states that the quality of the user interface of an appliance is relatively unimportant in determining its adoption by users if the perceived value of the appliance is high. Heckel’s inverse law states the importance of the user interface design in the adoption of an appliance is inversely proportional to the perceived value of the appliance. Although the usability of the UI is important, the overriding concern is the usefulness of the device itself.
- 7. Implicit HCI motivation Explicit HCI (eHCI) design supports direct human intervention. Pure explicit interaction is context free. Users must repeat and reconfigure the same application access every session even if every session repeats itself. It is also more about H2C (Human to Computer) Interaction. Focus is on the human having a model of the system (a mental model) rather than the system having a model of the individual user.
- 8. Implicit HCI (iHCI) Eg: Person entering dark room Its an action, performed by the user that is not primarily aimed to interact with a computerised system but which such a system understands as input. Context aware C2H (Computer to Human) Interaction Computer has a certain understanding of users’ behaviour in a given situation(additional input) Complex to design than eHCI.
- 9. Complexity and challenges of iHCI To accurately and reliably determine the user context Systems may also require time in order to learn and build an accurate model of a user. The user context determination may invade and distract users’ attention
- 10. Ubiquitous audio video content access
- 11. Continued… Individual voice, video and audio services are often not aware of each other and sometimes are not user configurable. Eg: when a voice call arrives, TV and radio are automatically paused or muted. Voice calls can be recorded in answer phone devices but they cannot easily be exported or reformatted. To support such dynamic service composition requires the use of a pervasive network infrastructure, standard multimedia data exchange formats and certain metadata.
- 12. Ubiquitous information access and E-books Personal digital calendar- can be accessed through different devices. Pull type interaction allows users to initiate the information exchange eg: searching the web. Push type notification services are used for customers to be notified of events, e.g., news. PC remained the dominant interactive information access device, but not in all cases eg: kitchen , which motivated use of mobile devices. Electronic information access is better as compared to papers.
- 13. Universal local control of ICT system
- 14. User-Awareness and Personal Spaces Personalization can make the system customized. Configuration of services can also be personalized. Eg: coordinate and configure different home appliances Complex issue is to manage shared social spaces.
- 15. Diversity of ICT Device Interaction Usually PC is a device with programmable chip, haptic i/o, visual UI. Embedded system in a device to perform specialised task have different i/o interfaces Devices characterised based on Size: Haptic input: Interaction modalities: Single user versus shared interaction: Posture for human operator: Distance of output display to input control: Position during operation: Connectivity: Tasking: Multimedia content access: Integrated:
- 16. UI and Interaction for Four Widely Used Devices Personal computer , Hand held mobile devices used for communication, Games consoles and Remote controlled AV displays, players and recorders.
- 17. PC Interface Early interfaces- command based In 1995 WIMPS interface had been introduced WIMPS- not only commands but interactive screen objects can be controlled WIMPS(window, icon, menu, pointer devices) Most dominant interface- can perform direct manipulations
- 18. WIMPS interface WIMPS interface is associated with a desktop metaphor. Documents-Windowed areas of the screen. Windows can be arranged in stacks, created, discarded, moved, organized and modified on the display screen using the pointer device(Direct manipulation) Advantages of theWIMPS UI over the command UI Order of multiple command is adhoc Users do not need to remember command names
- 19. Dialogues in WIMP Dialogues-users are informed about pertinent information that they must acknowledge receipt of or they ask for input to constrain a query. Typically displayed as a pop up window called a dialog box. Eg. Form filling dialog interfaces are used by many applications for alpha numeric data input These enable applications to receive data input in a structured way, reducing the processing used by a computer.
- 20. Drawbacks of WIMP not necessarily an improvement for visually impaired users consumes screen space which is more critical in lower resolution displays; the meaning of visual representations may be unclear or misleading to specific users; mouse pointer control and input require good hand eye coordination and can be slow.
- 21. Mobile handheld device interface PC style WIMPS not effective on mobile devices Display area is smaller. It is impractical to have several windows open at a time. It can be difficult to locate windows and icons if they are deeply stacked one on another Difficult to resize windows. Screen navigation using fingers on a touch pad or an external device may be too big and unwieldy for small devices. In addition, the keyboard is smaller for user input and there is a greater variety of input devices. Instead of using the inbuilt device interface, the device can be attached to different kinds of external input interface
- 22. Handling limited key input Different modes- limited number of keys and the minimum key size Same interface interaction can lead to different action Multi-Tap, T9, Fastap, Soft keys and Soft Keyboard 1. Multitap-12 keys having combinations(Explicit) 2. T9 –enhances experience of multitap(implicit) 3. Fastap-two keypads, one with smaller keys raised at the corners above the other keypad keys. The upper one is used for alphabetic input, the lower one for number input, If several keys are hit at once, a technique called passive chording allows the system to work out what the user intended to enter.
- 23. Continued.. 4. Soft keys-two left and right keys at the top of keypad to be determined by information on the screen; Allows the same keys to be reused to support application and task specific choices. Instead of having two soft keys, a whole mini keyboard, a soft keyboard, could also be displayed if there is sufficient screen space. Internal pointer devices -tracker pad, roller pads, mini joysticks ,keyboard arrow keys can be used to move the pointer on the screen. Touch screens whose areas can be activated using some physical stick like pointer, pen or a finger Auditory interfaces –voice commands
- 24. Handling Limited Output If output is too large- cropped ,content resolution can be reduced or a zooming interface can be used. Zooming (in and out) coupled with scrolling (up and down) and panning (side to side) control. Marking which part of the whole view that is currently zoomed in -useful for orientation. Peephole display- Sensors determine the position of the device in relation to the user Use of projectors or organic displays(foldable) Audible outputs(visual output already engaged) Haptic outputs(urgency of call can be conveyed from the vibrations)
- 25. Games console interface Seven different generations of games consoles based upon the technologies they use. Current, seventh generation, game consoles include the Nintendo Wii Nintendo -micro sensors in the form of accelerometers located inside the controller and an infrared detector to sense its position in 3D space. Scoring system -tuned to the interface(as the game progresses, it becomes difficult to score points) Wii wand(natural interface)-easy for user to interact with the system and immersed in the virtual game environment.
- 26. Localised remote control To reduce the degree of manual interaction Design issue- overlapping features ,devices need to be orchestrated with respect to a common feature. Eg: increasing volume of home entertainment system Solution-universal localised remote control
- 27. Universal local remote control
- 28. Hidden UI Via Basic Smart Devices WIMPS is more obtrusive-needs users to think continuously More natural interfaces are required –gestures, senses, speech etc Multimodal interface , gesture interface, natural language interfaces
- 29. Multimodal interface Modality- mode of human interaction using one of the human senses-5 senses human senses such as cameras ,touch screens, microphones ,chemical sensors . Majority of ICT system have single mode- but human interaction is multimodal. Eg: attentive interface-rely on attention wearable interface- worn by user vision based human motion analysis system
- 30. Gesture interface Meaningful and expressive body movements Can be sensed by wearable device-gloves magnetic trackers body attachments- accelerometers, gyroscopes computer vision techniques Two types of gestures Contactful gesture-handshake, use of touchscreen Contactless gesture- waving at someone Eg: Sony’s eye toy, current devices having gyroscope
- 32. Reflective Versus Active Displays Ebooks are light weight, thin, long lasting powered, pocket sized devices with touch screens enabling pages to be turned by touch. It differs in type of display it uses- reflective No energy required, readable in sunlight, can be read from any direction Based on electrophoretic display EPDs –electrophoretic phenomenon of charged particles suspended in a solvent. Displayed text and images can be electrically written or erased repeatedly
- 34. Combining I/O interfaces Resistive v/s capacitive touchscreen TUI –augmenting real physical world by connecting digital information to everyday physical objects and environments. Eg of TUI are ambient wood, datatiles Organic interface-resemble natural human -physical and human-human interaction Eg: Organic Light Emitting Diode (OLED) display
- 35. Advantages of OLED Lower cost Lightweight and flexible Good resolution Wider viewing angles and improved brightness Power efficiency Eg: samsung galaxy note edge, LG G Flex
- 36. Auditory interface Communicative connections between machine and user Replacement to keyboard text For visually impaired users Challenges- noise removal, ambiguity of commands
- 37. Hidden UI Via Wearable and Implanted Devices Device can be – accompanied, wearable, implanted Accompanied-external to body, not attached- mobile device, smart cards Wearable-external but attached to body-hearing aids, earpieces Implants-internal to body-medical purposes Eg: Eyetap, head-up-display, clothes as computer, computer implants
- 38. Human centered design life cycle
- 39. Activities of HCD 1. Define the context of use in terms of scenarios, use cases, task models, and the ICT, physical and social environment context of use. 2. The stakeholder and organizational requirements must be specified. 3. Multiple alternative UI designs need to be built. 4. Designs need to be validated against user requirements.