From: Human Factors International hfi@humanfactors.com
Date: Wed, 26 Dec 2001 10:55:22 -0600

USER INTERFACE DESIGN UPDATE - December, 2001

Insights from Human Factors International, Inc. (HFI)
Providing consulting and training in software ergonomics.
(http://www.humanfactors.com/)

Every month HFI reviews the most useful developments in
UI research from major conferences and publications.
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In this issue:

Dr. Bob Bailey offers research-based observations -- a year-end
list of design "Dos and Don'ts" that all have recent research to
support them.

The Ergonomic Pragmatist, Dr. Eric Schaffer, gives practical advice.
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Bob Bailey, Ph.D., Chief Scientist for HFI

Every year since 1983, I have reviewed (and summarized) most
of the usability-related research literature that was published during
the previous year. This has provided the basis for the popular,
annual 3-day User Interface Update course. My annual two-month
read and review activity provides me with a number of research-
based insights into "what works" and "what does not work" in
usability. I have listed some of these insights below. What makes
these "Do's and Don'ts" unique is that they all have recent research
to support them.

General Observations
  1. Do ensure that pages are "physically consistent" within and
      between Web pages.
  2. Do use independent individual, and then group, decisions when
      designing interfaces.
  3. Do attempt to identify the mental model held by typical users.
  4. Do ensure that the activities allocated to be performed either by
      the human or the computer take full advantage of the strengths
      of each.

Interaction Issues
  5. Do use "point-and-click" on each desired menu item and do
      not use "cascading mouse-overs" that make cascading menus
      automatically open.
  6. Do use "sequential menus" for simple forward-moving tasks, and
      use "simultaneous menus" for tasks that would otherwise require
      numerous uses of the Back button.

Display Issues
  7. Do not use fonts that are less than 5 points in height (5/72 of an
      inch on the monitor).
  8. Do use black text on a plain background (one that does not
      have a pattern) when users are expected to rapidly read and
      understand prose text.
  9. Do select color combinations that can be discriminated by
      individuals with color vision deficiencies.
10. Do use an appropriate palette to simulate the colors as
      perceived by color deficient individuals once color decisions
      are made.
11. Do increase the lightness contrast between foreground and
      background colors to accommodate users with color vision
      deficiencies.
12. Do provide animation of an item to which users should first
      attend.
13. Do put important information in a page area that users
      perceive as "larger."
14. Do not assume that users will read the associated text
      captions for images.
15. Do put the most important information on the home page at
      the top-middle of the page.
16. Do assume that users will scan all related items in one area
      before moving to another area of the page.
17. Do use animated icons rather than complex static icons to
      convey icon meaning for new or occasional users.
18. Do use simple icons rather than complex icons for new or
      occasional users.
19. Do use either synthesized speech or recorded human speech
      when having the computer "talk" to users.
20. Do use male not female synthesized voices to enhance
      comprehension of synthesized speech.

Web Site Design Issues
21. Do ensure that each page loads in 5 seconds or less.
22. Do ensure that Web pages load quickly because users believe
      that slow-loading pages suggests that the products being sold
      are of inferior quality, and that the security of any purchase
      may be compromised. Also, users rate pages with long delays
      as being less interesting, and more difficult to scan.
23. Do provide useful content on the home page or within one
      click of the home page.
24. Do provide appropriate and consistent navigation within a
      Web site.
25. Do provide a search capability that retrieves all relevant items
      and lists them in a useful order.
26. Do provide an efficient and easy-to-understand checkout
      process.
27. Do provide "glosses" to help prevent users from selecting
      a wrong link.
28. Do show as much information as possible above the ‘fold’
      on each page to facilitate navigation.
29. Do ensure that link labels are well understood by typical
      users particularly when many clicks (more than two) are
      necessary to acquire a target.
30. Do provide "templates" to facilitate use of search engines.
31. Do not provide complex search capabilities.

Prototyping and Usability Testing
32. Do sketch the initial prototype using a tool such as Denim
      (stylus and pad).
33. Do use appropriate "automatic evaluation" methods to
      conduct initial usability testing on Web sites.
34. Do keep in mind that both "heuristic evaluations" and
      "cognitive walkthroughs" methods will miss many usability
      problems, and they will detect about as many false positives
      as they do actual problems.
35. Do use enough test subjects when "performance testing" to
      satisfy the usability goals set by management. For example,
      if management wants 90% of typical users performing a
      specific task to have no problems then use a minimum of
      22 subjects.
36. Do recognize that different testers and different test groups
      have unique perspectives when using "performance tests" to
      detect and report usability problems.
37. Do provide nine response categories for each item when
      having users rate items in Web sites.
38. Do conduct "before and after" studies when revising Web sites.
      This will help demonstrate the value of applying the usability
      technology.

User Characteristics
39. Do keep in mind that when users must read and remember
      information on one page for use on another page, they only can
      remember about 3 or 4 items.
40. Do keep in mind that older adult users have reduced "working
      memory" capacity.
41. Do not require users to perform other tasks using "working
      memory" at the same time they are reading from a page -- it will
      slow their reading speed.

Note: the references for these do's and don'ts
will  be posted on the HFI Web site early January at
http://www.humanfactors.com/library/dec01.asp
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The Ergonomic Pragmatist
Eric Schaffer, Ph.D., CPE, Founder and CEO of HFI

Impressive list of recommendations! Read through them. You will
probably find that most of them make sense and fit with your
experience. But you may find some that are new, different, or don't
seem right. That is what studies are FOR. Every good usability
specialist builds a model of human behavior in their head. We can
look at most situations and anticipate pretty well what will happen.
The research lets you fine tune your model. Bob taught me (in 1977)
to read each study, then predict what the results will be. Then see if
the results fit your expectation. If they do not, try to figure out why.
Read the study in detail. Maybe it is not using the same users,
environment, or tasks. Just maybe, change your model a bit. Doing
that is what builds your value as a usability specialist. I still read,
get surprised, and learn more. I take Bob's course each year
because it is a rocket ship to learn more. And he will have to do
some explaining to me this year before I buy the idea of glosses.
May 2002 be a great year for Usability and a great year for you all.
__________________________________________________

3-day Annual User Interface Update Seminar presented by
Dr. Robert Bailey.
http://www.humanfactors.com/training/annualupdate.asp.
__________________________________________________

REGISTER for Bob's UI Update Seminar:

The schedule for 2002 seminars can be downloaded at
http://www.humanfactors.com/downloads/2002calendar.pdf
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Suggestions, comments, questions?
HFI editors at mailto:hfi@humanfactors.com.

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