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Learn about heuristic evaluation, usability risks, essential guidelines, and design principles. Explore examples and best practices for effective system design.
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Information System DesignInfo-440 Autumn 2002 Session #17
Agenda • Heuristic evaluation • What is it & how it works? • Examples • Return Quiz
Admin • Announcements • To do: Will schedule some kind of Visio lab • Topics that you would like to know more about?
Upcoming • Assignment #4 • December 4 • Final quiz • December 9 • Will be on Nielsen, Chapter 5 only
Heuristic Evaluation • Goal: Uncover usability risks (problems) • How: Careful inspection of an interface • What is the challenge?
The process • Focus on a part of the UI • Decide upon a use scenario • Develop a list of goals • Select some guidelines/heuristics • Depends on need/purpose • Inspect the UI against the guidelines • Identify risks
Essential ideas • Aim for good coverage • Drive your analysis from a scenario • Aim to be systematic • Select appropriate guidelines • Aim for nuanced judgment • Issues have varying degrees of risk • Aim to develop special-purpose guidelines • Draw on the work of others & your experience • Practice, practice, practice
Some issues • Standards vs. guidelines • ‘Standards’, once set, are not negotiable • General vs. specific guidelines • Understanding and applying guidelines is not easy • Multiple evaluations • More eyes are better than one • Guidelines need to be revised over time • Sometime you get a guideline wrong
Let’s examine some guidelines • “Keep things visible” (Norman) • “When all else fails, be consistent” (Norman) • “Simple and natural dialog” (Nielsen) • “Minimize user memory load” (Nielsen) • “Good error messages” (Nielsen) • “Prevent errors” (Nielsen) • Comments?
Jeff Johnson (GUI Bloopers) • Focus on the users and their tasks, not the technology • Consider function first, presentation later • Conform to the users’ view of the task • Don’t complicate the users’ task • Promote learning • Deliver information, not just data
Jeff Johnson (GUI Bloopers) • Principle 3: Conform to the users’ view of the task • Strive for naturalness • Use users’ vocabulary, not your own • Keep program internals inside the program • Find the correct point on the power/complexity trade-off
Bloopers is a wonderful book • Area: GUI Component Bloopers • Section: Complicating access to functionality • Example: Blooper 1: Dynamic menus (Hundreds and hundreds of examples)
Macintosh UI Guidelines Save changes to the X document “Special Memo” before closing Don’t save Cancel Save
Macintosh UI Guidelines Save changes to the X document “Special Memo” before closing Don’t save Cancel Save Data loss Safe for data
Section 508 guidelines • A text equivalent for every non-text element shall be provided (e.g., via "alt", "longdesc", or in element content). • Every image, Java applet, Flash file, video file, audio file, plug-in, etc. has an alt description. • Complex graphics (graphs, charts, etc.) are accompanied by detailed text descriptions. • The alt descriptions succinctly describe the purpose of the objects, without being too verbose (for simple objects) or too vague (for complex objects). • Alt descriptions for images used as links are descriptive of the link destination. • Decorative graphics with no other function have emptyalt descriptions (alt= ""), but they never have missing alt descriptions.
Section 508 guidelines • A text-only page, with equivalent information or functionality, shall be provided to make a web site comply with the provisions of this part, when compliance cannot be accomplished in any other way. The content of the text-only page shall be updated whenever the primary page changes.
Special purpose guidelines • Website design guidelines for • People who are blind • People who are under 14 • Website design guidelines for • Personalization sites • Site maps • E-commerce
Multiple evaluators • The data suggests that different analysts uncover different problems • Therefore, to get a complete list, you should have 2-4 people evaluate a UI for issues
What about this guideline? Only 10% of users scroll beyond the information that is visible on the screen when a page comes up. All critical content and navigation options should be on the top part of the page. [from 1999]
Let’s practice: Examples from Interface Hall of Shame & Web Bloopers Archive (http://www.iarchitect.com/mshame.htmhttp://www.uiwizards.com/wBloopArchive.html)