HCI guidelines - use and misuse

1. HCI guidelines - use and misuse Susan Turner

2. Now and next in MSD... • This week - guidelines • week 10 - case study & exam question • week 11 - your turn • research either • HCI issues in the design & evaluation of virtual reality • HCI issues in the design & evaluation of small mobile devices

3. Today’s lecture • Using guidelines and standards sensibly • Guidelines exercise • Guidelines for universal access

4. Guidelines and standards • Guidelines • general purpose ‘rules’ in HCI texts and websites • most useful when include explanatory text • in-house and proprietary style guides • Standards • have formal authority

5. From Smith & Mosier (1986) ftp://archive.cis.ohio-state.edu/pub/hci/Guidelines/guidelines

6. Shneiderman’s 8 golden rules of dialogue design • Strive for consistency • Enable frequent users to use shortcuts • Offer informative feedback • Design dialogs to yield closure • Offer simple error handling • Permit easy reversal of actions • Support internal locus of control • Reduce short-term memory load

7. Hix and Hartson’s guidelines

8. Hix and Hartson (2)

9. Apple guidelines for shortcuts

10. Guidelines for web design • www-3.ibm.com/ibm/easy/eou_ext.nsf/Publish/572 • try also www.useit.com (Jakob Nielsen’s site)

11. Using Guidelines • guidelines often conflict in specific instances • helps to understand the underlying reasoning • consider the requirements of the situation and decide which aspects are most important • basis of ‘heuristic evaluation’ (more in later lecture) • a collection of guidelines links • www.ida.liu.se/~miker/hci/guidelines.html

12. Standards • Set by (inter)national standards bodies, but often industry driven • International Standards Organisation (ISO) • International Telegraph and Telephone Consultative Committee (CCITT) • British Standards Institute (BSI) • American National Standards Institute (ANSI) • prescriptive, rather than advisory

13. For example • ISO 9241 Ergonomics for Office Work with Visual Display Terminals • ISO 14915 Ergonomics for Multimedia User Interface Design • BSEN ISO 13407 ‘Human Centred Design for Interactive Systems’ • conformance usually by process not product • also European directives (e.g.90/270/EEC)

14. General introduction Guidance on task requirements VDU requirements Keyboard requirements Workstation layout and postural requirements Environmental requirements Display requirements with reflections Requirements for displayed colours Requirements for non-keyboard input devices Dialogue principles Guidance on usability specification and measures Presentation of information User guidance Menu dialogues Command dialogues Direct manipulation dialogues Form-filling dialogues ISO 9241

15. ISO 9241 example

16. European directive of 29.5.90 • minimum health & safety requirements for employees who work with display screens • wide exceptions • employers’ obligations

17. In summary • Guidelines can be useful, but need thought in their application • Be aware of HCI standards

18. Designing for universal use

19. Universal design “Universal design for telecommunications and information systems means designing products which can be effectively and efficiently used by people with a wide range of abilities or in a wide range of situations.” Universal Access Project, University of Wisconsin, 1995 • need to be aware • as users • as designers and implementers • as support engineers

20. Justification for universal design • Legal and ethical rights • e.g. Disability Discrimination Act (UK) • Contribution to a more open society • move away from ‘disability products’ • Broader market • expansion of technology into new domains and for new users • aging population • Broader application area • not just people with special needs, but ordinary people in special circumstances (low light, wearing gloves, noise…)

21. Aging computer users...

22. Relevant human abilities & design • Think about abilities, not types of people • vision • hearing • cognition • mobility and dexterity • designing for the elderly and children • some or all of these may be relevant • design proactively • avoid inadvertent exclusion • design to be accessible, usable and and acceptable

23. Ways of widening access • New features for hardware and operating systems • features universally available for compliant applications • Assistive technologies • enhance accessibility, but must be moved between computers • cost issues • Specialised applications • e.g. browsers which read pages • but people with special needs often work alongside others with standard applications • Usability features for mainstream applications • e.g. customisable colours to maximise contrast & therefore readability

24. Some assistive technologies • Screen enlargers • like a magnifying glass • can set and move area of focus • Screen reviewers or readers • make text available as speech or as Braille • graphics only included if alternative text provided • Voice input • not just text, but also as substitute for mouse/keyboard control • On-screen keyboards • select keys using alternative input devices • keyboard filters • compensate for tremor, erratic motion, slow response time...

26. Did you know? • Windows Accessibility Options (under control panel) • keyboard • sound • visual warnings & captions for sounds • display • high contrast options • mouse

27. A general approach • Requirements/specification • include people with special needs in requirements analysis and testing of existing systems • consider whether new features affect users with special needs (positively or negatively) and note this in specification • Design • take account of guidelines • Testing • include evaluation against guidelines • include special needs users in usability testing and beta tests • Implementation • make sure programming team are aware of guidelines • if prioritising bugs for fixing, consider that some may have disproportionately more impact on users with special needs

28. Basic principles of accessible design • Flexibility • customisable user interface to accommodate preferences • e.g. font size, menu arrangement • Choice of input and output methods • e.g. keyboard as well as mouse • redundant combinations of sound, graphics and text • Consistency • within and between applications

29. Prioritise • Number of users • give higher priority to features that affect more users • e.g. more people view documents than author them • Frequency of use • Necessity of use • give priority to features which are central to the product

30. Some useful links www.microsoft.com/enable* • detailed guidelines for Microsoft applications and more general advice www.abilitynet.co.uk • general advice on computing and related technologies for people with special needs www.cast.org.uk/bobby • web site checking service - also provides guidelines *acknowledgment: much of previous material derived from here

31. A specific example - designing for low vision (1) • Key principles - redundancy and flexibility • Keep to standard menu and dialogue box layouts • helps to memorise position of options • Provide keyboard alternatives • Use audio ‘tooltips’ • Supplement visual prompts with audible signals (or vibration or tactile output, such as to Braille display) • Use shading and patterns for visual items to supplement colour

32. Designing for low vision (2) • Use characters of at least 7.5 mm or 16 point on screen • Use San Serif font for labels, etc., Serif font for text • Generally, dark letters on light background are preferable • Allow messages to remain on the screen until dismissed by the user • Allow text to be enlarged and colours, contrast and brightness to be adjusted • Provide documentation in media which will allow users to listen to it

33. In summary • Be aware that guidelines and accesibility aids exist • Wherever possible, design for inclusion rather than exclusion