1. Usability Heuristics John Kelleher (IT Sligo)

2. 1 "The two most important tools an architect has are the eraser in the drawing room and the sledge hammer on the construction site." Frank Lloyd Wright

3. 2 Usability Heuristics 1. Visibility of system status 2. Match between system and the real world 3. User control and freedom 4. Consistency and standards 5. Error prevention 6. Recognition rather than recall 7. Flexibility and efficiency of use 8. Aesthetic and minimalist design 9. Help users recognize, diagnose and recover from errors 10. Help and Documentation

4. 3 1. Visibility of System Status Exact information provided at the exact moment User model = Designer model Natural mapping between system and user concepts Less is More less to learn, to get wrong, to distract… Information should appear in natural order related information is graphically clustered order of accessing information matches user’s expectations Remove or hide irrelevant or rarely needed information competes with important information on screen Remove modes or make highly visible Use windows frugally don’t make navigation and window management excessively complex 

5. 4 2. Match between system and the real world System should speak the users' language View from user’s perspective, not system. Adopt words as proposed by users into the I/F (problematic) Any set of terms eventually internalised. Synonyms (aliases) should be liberally used. 

6. 5 3. User control and freedom Users often choose system functions by accident (or exploration) Will need clearly marked ‘emergency’ exit If difficult to exit, then make difficult to enter E.g. Don’t break ‘Back’ button in browser Provide ‘Where am I?’ clues Exits must be visible not ‘taught or sought’.

7. 6 4. Consistency and Standards Facilitates exploratory learning. Consistency of effect same words, commands, actions will always have the same effect in equivalent situations Consistency of input Consistency of layout Same information/controls in same location on all screens / dialog boxes same visual appearance across the system (e.g. widgets) e.g. financial documents showing past years to the right E.g. web link formatting and dHTML

8. 7 Consistency and Standards

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11. 10 5. Error Prevention Even better than good error messages is a careful design which prevents a problem from occurring in the first place. Most commonly expressed as going to a site contrary to your intent Web links should be properly annotated Off-site Plug-ins required Large files No accepted conventions for presenting this information

12. 11 Dealing with errors… Adobe's ImageReady AutoCAD Mechanical Windows Notepad Microsoft's NT Operating System

13. 12 6. Recognition rather than recall Make objects, actions, and options visible. The user should not have to remember information from one part of the dialogue to another. Instructions for use of the system should be visible or easily retrievable whenever appropriate.

14. 13 7. Flexibility and efficiency of use Support expert use beyond novice. Accelerators, templates (styles), macros. Type-ahead Bookmarks (Web, Explorer shortcuts, Photoshop actions. Reuse of interaction history. 60% of WWW pages are revisits Format Paintbrush Recent document list Judicious use of default values. 

15. 14 Scrolling controls for page-sized increments Double-click raises toolbar dialog box Double-click maximises window to fill screen Customizable toolbars and palettes for frequent actions Split menu, with recently used fonts on top Keyboard accelerators for menus Double-click to preview/change design scheme

16. 15 8. Aesthetic and minimalist design "Dialogues should not contain information which is irrelevant or rarely needed. Every extra unit of information in a dialogue competes with the relevant units of information and diminishes their relative visibility.“ Avoid starving the user of information Reveal progressive levels of information to cater for spectrum of users Always rewrite paper content for web Beware of content management software Links are veins of communication

17. 16 9. Help users recognize, diagnose, and recover from errors Error messages should be expressed in plain language (no codes), precisely indicate the problem, and constructively suggest a solution. Errors will happen, despite all your efforts to prevent them. Every error message should offer a solution (or a link to a solution) on the error page. For example, if a user's search yields no hits, do not just tell him to broaden his search. Provide him with a link that will broaden his search for him. Look at MS search results page

18. 17 Consumer Manuals...

19. 18 10. Help and documentation Not for leveraging a poor interface. Design for task-oriented search rather than reference. On-line documentation. Superbook Online help extend the breadth of the interface. Online help should be context sensitive. Quality of help text more significant than access mechanism. ‘Search, Understand, Apply’ user strategy. Search: provide rich indexing of terms. Understand: self-contained examples. Apply: help text and problem side-by-side. Meta-manuals? 

20. Documentation and how it is used Many users do not read manuals prefer to spend their time pursuing their task Usually used when users are in some kind of panic, need immediate help indicates need for online documentation, good search/lookup tools online help can be specific to current context paper manuals unavailable in many businesses! e.g. single copy locked away in system administrator’s office Sometimes used for quick reference syntax of actions, possibilities... list of shortcuts...

21. 20 Types of Help Tutorial and/or ‘Getting Started’ manuals Short Guides encourage exploration initiates build of conceptual model On-line tours illustrates basic principles through worked examples. E.g. Flash Reference manuals Mostly by experts for detailed lookup rarely introduces concepts thematically arranged On-line hypertext search toc index cross index

22. 21 Documentation

23. 22 Types of Help (contd.) Reminders Short reference cards expert users wanting to check some facts novice who wants an overview of system capability Keyboard templates shortcuts/syntactic meanings of keys; recognition vs. recall; capabilities Tooltips text over graphical items indicates their meaning or purpose. Context-Sensitive Help Mac ‘Balloon help’ Windows ‘What’s this?’ Wizards Walks though typical task Dangerous if user gets stuck Tips regarding current user practice