|
|
UI Design Update
Newsletter – December, 2002
Insights from
Human Factors International
| In
This Issue: |
|
|
| |
|
|
| Research-Based
Observations |
|
Bob
Bailey, Ph.D., Chief Scientist for HFI, provides a year-end list of
do's and don'ts that have recent research to support them. |
| |
|
|
| The
Ergonomic Pragmatist |
|
Dr.
Eric Schaffer, Ph.D., CPE, founder and CEO of HFI offers practical
advice. |
| |
|
|
| |
|
See
what Usability
News has to say about this newsletter. |
| Research-Based
Observations |
| |
|
|
|
|
|
Every year
since 1983, I have reviewed and summarized much 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
outline" activity provides me with a number of research-based
insights into "what works" and "what does not work"
in usability. I have listed many of these insights in this article.
What makes these "Do's and Don'ts" unique is that they
all have recent research to support them.
|
|
| General
Observations |
|
| 1.
|
Do evaluate the goodness of a Web site by evaluating content,
navigation, visual design, functionality and interactivity,
but realize that these elements are not totally independent
(i.e., Web site evaluators have a difficult time separating
them from each other).
|
| 2.
|
Do make
Web sites appear more credible by:
- Making
it easy to distinguish ads from content,
- Providing
quick responses to customer's service questions,
- Listing
the organizations physical address,
- Having
an organization that is well respected outside of the Internet,
- Updating
the site frequently with new content,
- Allowing
users to search past content, and
- Providing
a professional looking Web site.
|
| 3.
|
Do
use Flash to enhance interfaces knowing that 98% of browsers
are capable of playing Flash without downloading.
|
| 4. |
Do
design Web application (Weblications) interfaces different than
traditional Web site interfaces.
|
| 5. |
Do use
"parallel design" concepts when designing user interfaces,
because participants:
- Can
reach a consensus quickly,
- Will
consider numerous different design alternatives, and
- Respond
to good ideas even when they are contained in poor designs.
|
|
|
| Display
Issues |
|
| 6.
|
Do
use good headlines when designing newspaper, newsletter and
other information-based sites because eye tracking studies show
that users tend to look first at text, not images (a margin
of nearly two to one favoring text).
|
| 7.
|
Do consider
the size of textual information to be used as entry points,
because
- When
text and images are of similar size, text is more likely
to be an entry point,
- Images
must be much larger than text to act as an entry point,
and
- Larger
text dominates over smaller text (normal sized text rarely
acts as an entry point – even if bold or a hyperlink).
|
| 8.
|
Do put
the most important prose text and bullet item information
toward the top left of a page, because users tend to scan
from left to right, and top to bottom when reading, but do
not follow the same pattern between images, titles
or links.
|
| 9.
|
Do
use common and contiguous background colors to help guide users
in finding information on a page.
|
| 10. |
Do put
the most important information on a Web page at the middle-top
of the page because that text:
- Will
be seen first, and
- Text
at the bottom of a page is rarely seen.
|
| 11. |
Do use
right and left panels for links, because users will investigate
areas outside the center area:
- When
searching for a specific link, and
- When
visiting a Web site after the first time.
|
| 12. |
Do not use fonts on Web pages that are less than 10 points.
|
| 13. |
Do
use 12-point fonts (size=3) on Web pages to elicit optimal reading
speed for most adults.
|
| 14. |
Do
use any of the most common font styles (e.g., Arial, Verdana,
Georgia, Times New Roman), either serif or sans serif fonts,
to elicit the fastest possible reading speed.
|
| 15. |
Do
use sans serif fonts (e.g., Arial, Verdana) to satisfy user
preferences.
|
| 16. |
Do
use 14-point fonts for older users.
|
|
|
| Interaction
Issues |
|
| 17.
|
Do
carefully consider the task being performed before making decisions
about the breadth and depth of a Web site, because sites with
numerous levels may or may not degrade performance.
|
| 18.
|
Do carefully
consider the task being performed before making decisions
about using or not using frames, because some uses of frames
will degrade performance.
|
| 19.
|
Do not consider users' judgments about "ease of
use" as accurately representing the speed with which a
task can be performed.
|
| 20.
|
Do use similar item justification and scroll bar orientation
to produce reliably faster selection times, fewer errors and
improved preferences in the use of list boxes (and possibly
Web site scrollbars).
|
| 21. |
Do consider the experience level of users and "frequency
of use" when selecting widgets in Web sites, particularly
when deciding between using entry fields and dropdown lists
(experienced users are faster with entry fields).
|
| 22. |
Do place commonly selected objects close to the edge of a window
to expedite their selection.
|
| 23. |
Do not be concerned that frequent keyboard use will cause
carpal tunnel syndrome.
|
|
|
| Web
Site Design Issues |
|
| 24.
|
Do
design Web sites primarily for use with the Microsoft's Windows
operating system, unless different (more specific) information
about the operating systems being used by the target audience
is available.
|
| 25.
|
Do
design Web sites primarily to be displayed by the Internet Explorer
and Netscape browsers.
|
| 26.
|
Do design Web sites to work best with screen resolutions of
the majority of typical users, which worldwide is now 800x600
pixel resolution.
|
| 27.
|
Do
design Web sites for use on monitors that show at least 256
colors.
|
| 28. |
Do design pages to load in a few seconds; however, keep in mind
that some users will rate the download speed of slow pages as
"fast" if they are able to successfully accomplish
what they intend to do.
|
| 29. |
Do
design a Web site that encourages either linking or searching
behaviors by users.
|
| 30. |
Do
design a search capability so that most users will complete
a successful search on their first attempt.
|
| 31. |
Do design
to encourage users to access links (not search) if it is important
for users to continue to browse the Web site after locating
their primary target, because:
- About
60% will continue to browse the site (only 20% of "searchers"
continued to browse)
- "Linkers"
are three times more likely to find related (valuable) content
- "Linkers"
who started with links on the homepage looked at almost
10 times more content pages
|
| 32. |
Do design
Web sites to have a "moderate amount" of white space,
because:
- Users
prefer a moderate amount of white space, and
- There
is no reliable performance differences with differing amounts
of white space.
|
| 33. |
Do design
Web sites using a "Fluid" layout, because:
- Users
believed that the "Fluid" layout was best for
reading and for finding information, and
- There
were no reliable performance differences among the methods
(left justified, centered or fluid).
|
| 34. |
Do design
Web sites with embedded links, because:
- Users
preferred having them embedded, and
- There
were no reliable performance differences between embedded
links and those outside the text.
|
| 35. |
Do
design Web sites with links that are both embedded and
outside the text on the left margin, because redundant links
were preferred by users.
|
| 36. |
Do
design Web sites with the links in a frame on the left margin,
because users preferred the frames rather than having the links
scroll off the page.
|
| 37. |
Do
design Web sites that enable textual chat (Instant Messaging)
between users and Web site assistants.
|
| 38. |
Do design
Web sites so that if users must be placed in a queue:
- They
can be continually updated, and
- The
updates can include sounds (so that users can work on other
things).
|
| 39. |
Do write
prose text in Web sites at appropriate reading levels for
the target audience as calculated using a commonly used readability
formula, because:
- The
average reading level in North America is at the eighth-
to ninth-grade,
- About
one in five adults read at the fifth-grade level and below,
and
- Adults
tend to read at least one or two grade levels below their
last school grade completed.
|
| 40. |
Do use
Rapid Serial Visual Presentation (RSVP) for presenting information
to users who need to read prose text from small displays (PDAs,
cell phones, wrist watches), because:
- RSVP
enables an acceptable level of reading performance, and
- There
is no performance or preference differences among 10-line,
3-line and RSVP.
|
| 41. |
Do
use 20-point text presented at speeds of about 250 wpm on RSVP-based
displays. |
|
|
|
Usability Testing |
|
| 42.
|
Do design "low word count" Web sites (average of 65
words) using fewer words, smaller page sizes, fewer graphics,
faster download times and more font variations (particularly
between header and body text).
|
| 43.
|
Do design "medium word count" Web sites (average of
230 words) using less body text, organized better into clusters
(lists and shaded table areas), using lower percent graphics,
and with more colors to help distinguish headers.
|
| 44.
|
Do design "high word count" Web sites (average of
800 words) using less body text, organized well into clusters
(lists and shaded table areas), with more text links, large
page size, lower percent graphics, and using more colors to
help distinguish headers.
|
| 45.
|
Do use eye-tracking methods to determine confusion rates from
users in usability testing.
|
| 46. |
Do require usability testing clients to make specific and focused
requests, including usability objectives, specific definitions
of success and clear time limits for task completion.
|
| 47. |
Do plan on inadvertently creating new usability problems when
fixing problems identified by previous usability testing.
|
| 48. |
Do plan
on finding and fixing about 37% of the problems in a system
with each performance test (i.e., each iteration), which means
that to detect and correct 95% of the usability problems it
would take
- At
least six tests, and
- 105
participants.
|
| 49. |
Do have
members of the design team use a prototype Web site to create
an estimate of the time it should take an experienced user
to access information; then use this time to set usability
objectives (e.g., 85% of the users shall not need more than
125% of the expert users' time for each task).
|
| 50. |
Do use
a "large" number of users (e.g., over 100) for performance
tests, because of:
- The
complexity of Web sites
- Hundreds
or thousands of pages
- Hundreds
of features and paths, and
- The
need to determine the prevalence of problems in target populations,
- Only
35% of problems were identified after testing five users.
|
| 51. |
Do use
automated testing methods for some, if not all, of the performance
testing for a new system, because automated testing allows:
- More
rapid data collection and analysis,
- The
use of a large numbers of users, and
- Quick
evaluation of content that keeps changing.
|
| 52. |
Do
provide online learning materials that primarily use a traditional
prose text format, because it elicits better learning (however
users preferred a hypertext format).
|
| 53. |
Do not
use testers or test participants to be involved in a test
when they have a cold, because:
- They
will respond more slowly,
- They
will detect fewer problems, and
- They
will have reduced energy and motivation levels.
|
|
|
| Users |
|
| 54.
|
Do use
the following age categories when designing and using study
information:
- Old-old:
75 and older
- Older:
60-74
- Middle-aged:
40-59
- Young:
18-39
|
| 55.
|
Do ensure that important system (Web site) sounds are louder
for older users.
|
| 56. |
Do
use TFT screens rather than CRT screens to elicit the fastest
possible reading performance from users (older users benefit
even more than younger users).
|
|
|
| References |
|
| 1.
|
Sinha, R., Hearst, M. and Ivory, M. (2001), Content or graphics?
An empirical analysis of criteria for award-winning Web sites,
7th Conference
on Human Factors and the Web.
|
| 2.
|
Fogg, B.J., Marshall, J., Laraki, O., Osipovich, A., Varma,
C., Fang N., Paul, J., Rangnekar, A., Shon, J., Swani, P. and
Treinen, M. (2001), What makes Web sites credible? A report
on a large quantitative study, CHI 2001 Proceedings,
3(1), 61-68.
|
| 3.
|
developer.viewpoint.com/.../vmp_distribution.pdf
|
| 4.
|
Wroblewski, L. and Rantanen, E.M. (2001), Design considerations
for Web-based applications, Proceedings of the Human Factors
and Ergonomics Society 45th Annual Meeting, 1191-1195.
|
| 5. |
McGrew,
J. (2001), Shortening the human computer interface design cycle:
A parallel design process based on the genetic algorithm, Proceedings
of the Human Factors and Ergonomics Society 45th Annual Meeting,
603-606.
|
| 6. |
Lewenstein,
M., Edwards, G., Tatar, D. and Devigal, A. Where do users look
first? Stanford
Poynter Institute Technical Report.
|
| 7. |
Faraday,
P. (2001), Attending to Web pages, CHI 2001 Proceedings.
|
| 8. |
Faraday,
P. (2001), Attending to Web pages, CHI 2001 Proceedings.
|
|
9.
|
Faraday,
P. (2001), Attending to Web pages, CHI 2001 Proceedings.
|
| 10. |
Faraday,
P. (2001), Attending to Web pages, CHI 2001 Proceedings;
and Schroeder, W. (2001), Testing Web sites with eye-tracking,
User
Interface Engineering Newsletter.
|
| 11. |
Schroeder,
W. (2001), Testing Web sites with eye-tracking, User
Interface Engineering Newsletter.
|
| 12. |
Tullis,
T.S., Boynton, J.L. and Hersh, H. (1995), Readability of fonts
in the windows environment, CHI 95 Extended Abstracts,
127-128.
|
| 13. |
Bernard,
M. and Mills, M. (2000), So what size and type of font should
I use on my Web site? Usability News, July, 2(2); Bernard,
M., Lida, B., Riley, S., Hackler, T. and Janzen, K. (2002),
A comparison of popular online fonts: Which size and type is
best? Usability News, January, 4(1); Bernard, M., Mills,
M., Peterson, M. and Storrer, K. (2001), A comparison of popular
online fonts: Which is best and when? Usability News,
July, 3(2); and Boyarski, D., Neuwirth, C., Forlizzi, J., and
Regli, S.H. (1998), A study of fonts designed for screen display,
CHI 98 Conference Proceedings, 87-94.
|
| 14. |
Bernard,
M. and Mills, M. (2000), So what size and type of font should
I use on my Web site? Usability News, July, 2(2); Bernard,
M., Lida, B., Riley, S., Hackler, T. and Janzen, K. (2002),
A comparison of popular online fonts: Which size and type is
best? Usability News, January, 4(1); Bernard, M., Mills,
M., Peterson, M. and Storrer, K. (2001), A comparison of popular
online fonts: Which is best and when? Usability News,
July, 3(2); and Boyarski, D., Neuwirth, C., Forlizzi, J., and
Regli, S.H. (1998), A study of fonts designed for screen display,
CHI 98 Conference Proceedings, 87-94.
|
| 15. |
Bernard,
M. and Mills, M. (2000), So what size and type of font should
I use on my Web site? Usability News, July, 2(2); Bernard,
M., Lida, B., Riley, S., Hackler, T. and Janzen, K. (2002),
A comparison of popular online fonts: Which size and type is
best? Usability News, January, 4(1); Bernard, M., Mills,
M., Peterson, M. and Storrer, K. (2001), A comparison of popular
online fonts: Which is best and when? Usability News,
July, 3(2); and Boyarski, D., Neuwirth, C., Forlizzi, J., and
Regli, S.H. (1998), A study of fonts designed for screen display,
CHI 98 Conference Proceedings, 87-94.
|
| 16. |
Bernard,
M., Liao, C. and Mills, M. (2001), Determining the best online
font for older adults, Usability News, January, 3(1).
|
| 17. |
Tsunoda,
T., Yamaoka, T., Yamashita, K., Matsunobe, T., Hashiya, Y.,
Nishiyama, Y. and Takahasi, K. (2001), Measurement of task performance
times and ease of use: Comparison of various menu structures
and depth on the Web, Proceedings of the Human Factors and
Ergonomics Society 45th Annual Meeting, 1225-1229.
|
| 18. |
Tsunoda,
T., Yamaoka, T., Yamashita, K., Matsunobe, T., Hashiya, Y.,
Nishiyama, Y. and Takahasi, K. (2001), Measurement of task performance
times and ease of use: Comparison of various menu structures
and depth on the Web, Proceedings of the Human Factors and
Ergonomics Society 45th Annual Meeting, 1225-1229.
|
| 19. |
Tsunoda,
T., Yamaoka, T., Yamashita, K., Matsunobe, T., Hashiya, Y.,
Nishiyama, Y. and Takahasi, K. (2001), Measurement of task performance
times and ease of use: Comparison of various menu structures
and depth on the Web, Proceedings of the Human Factors and
Ergonomics Society 45th Annual Meeting, 1225-1229.
|
| 20. |
Kellener,
E., Barnes, G.M. and Lingard, R. (2001), Effects of scroll bar
orientation and item justification when using list boxes, Proceedings
of the Human Factors and Ergonomics Society 45th Annual Meeting,
662-666.
|
| 21. |
Zavod,
M. J. and Fulop, A. C. (2001), Choosing input field formats
for use by sales personnel, Proceedings of the Human Factors
and Ergonomics Society 45th Annual Meeting 2001, 667-671.
|
| 22. |
Farris,
J.S., Jones, K.S. and Anders, B.A. (2001), Acquisition speed
with targets on the edge of the screen: An application of Fitts'
law to commonly used Web browser controls, Proceedings of
the Human Factors and Ergonomics Society 45th Annual Meeting,
1205-1209.
|
| 23. |
Stevens,
J.C. (2001), No link between carpal tunnel syndrome and workplace
computer use, Neurology.
|
| 24. |
www.thecounter.com
|
| 25. |
www.thecounter.com
|
| 26. |
www.thecounter.com
|
| 27. |
www.thecounter.com
|
| 28. |
Spool,
J. (2001), The truth about download time, User
Interface Engineering Newsletter.
|
| 29. |
Spool,
J. (2001), User Interface Engineering Newsletter, May.
|
| 30. |
Spool,
J. (2001), User Interface Engineering Newsletter, November
27.
|
| 31. |
Spool,
J. (2001), User Interface Engineering Newsletter, December
4.
|
| 32. |
Bernard,
M., Chaparro, B. and Thomasson, R. (2000), Finding information
on the Web: Does the amount of white space really matter? Usability
News – Winter.
|
| 33. |
Bernard,
M. and Larsen, L. (2001), What is the best layout for multiple
column Web pages? Usability
News – Summer.
|
| 34. |
Bernard,
M. and Hull, S. (2002), Where should you put the links? Comparing
embedded and framed/non-framed links, Usability
News – 4.1.
|
| 35. |
Bernard,
M., Hull, S. and Drake, D. (2001), Where should you put the
links? A comparison of four locations, Usability
News – Summer.
|
| 36. |
Bernard,
M., Hull, S. and Drake, D. (2001), Where should you put the
links? A comparison of four locations, Usability
News – Summer.
|
| 37. |
Aberg,
J. and Shahmehri, N. (2001), An empirical study of human Web
assistants: Implications for user support in Web information
systems, CHI 2001 Proceedings, 404-411.
|
| 38. |
Aberg,
J. and Shahmehri, N. (2001), An empirical study of human Web
assistants: Implications for user support in Web information
systems, CHI 2001 Proceedings, 404-411.
|
| 39. |
D'Alessandro,
D.M., Kingsley, P and Johnson-West, J. (2001), The readability
of pediatric patient education materials on the world wide Web,
Archives of Pediatrics and Adolescent Medicine, 155(7);
and www.med.utah.edu
|
| 40. |
Bernard,
M.L., Chaparro, B.S. and Russell, M. (2001), Examining automatic
text presentation for small screens, Proceedings of the Human
Factors and Ergonomics Society 45th Annual Meeting, 637-639.
|
| 41. |
Russell,
M.C. And Chaparro, BS (2001), Exploring effects of speed and
font size with RSVP, Proceedings of the Human Factors and
Ergonomics Society 45th Annual Meeting, 640-644.
|
| 42. |
Ivory,
M.Y., Sinha, R.R. and Hearst, M.A. (2001), Empirically validated
Web page design metrics, CHI 2001 Proceedings, 53-60.
|
| 43. |
Ivory,
M.Y., Sinha, RR and Hearst, MA (2001), Empirically validated
Web page design metrics, CHI 2001 Proceedings, 53-60.
|
| 44. |
Ivory,
M.Y., Sinha, RR and Hearst, MA (2001), Empirically validated
Web page design metrics, CHI 2001 Proceedings, 53-60.
|
| 45. |
Marshall,
S., Drapeau, T. and DiSciullo, M. (2001), Case study: Eye tracking
the AT&T customer service site, IBM Make It Easy 2001.
|
| 46. |
Kessner,
M., Wood, J., Dillon, R.F. And West, R.L. (2000), On the reliability
of usability testing, Carleton University Masters Thesis.
|
| 47. |
Tan,
W., Dahai, L., Bishu, RR, Muralidhar, A. and Meyer, J. (2001),
Design improvements through user testing, Proceedings of
the Human Factors and Ergonomics Society 45th Annual Meeting,
1181-1185.
|
| 48. |
Tan,
W., Dahai, L., Bishu, RR, Muralidhar, A. and Meyer, J. (2001),
Design improvements through user testing, Proceedings of
the Human Factors and Ergonomics Society 45th Annual Meeting,
1181-1185.
|
| 49. |
Etgen,
M. and Cantor, J. (1999), What does getting WET (Web Event-logging
Tool) mean for Web usability? User Experience Engineering
Division, AT&T Labs.
|
| 50. |
Kangas,
S. (2001), Is
5000 users enough?; Schulman, D. (2001), Quantitative usability:
Extending lab research for larger sample sizes, IBM Make
it easy – 2001; and Spool,
J. and Schroeder, W. (2001), Testing Web sites: Five users is
nowhere near enough, CHI 2001.
|
| 51. |
Schulman,
D. (2001), Quantitative usability: Extending lab research for
larger sample sizes, IBM Make it easy – 2001.
|
| 52. |
Caldeira,
P.Z. (2001), Impact on learning and satisfaction of Web-based
learning systems: A comparison of linear vs. hypermedia presentations,
Proceedings of the Human Factors and Ergonomics Society 45th
Annual Meeting, 1235-1239.
|
| 53. |
Matthews,
G., Warm, J.S., Dember, W.N. (2001), The Common cold impairs
visual attention, psychomotor performance and task engagement,
Proceedings of the Human Factors and Ergonomics Society 45th
Annual Meeting 2001, 1377-1381.
|
| 54. |
Bailey,
R.W. (2002), When considering the age of users, How old is "old?"
Human Factors International Newsletter, July, 2002; and
Nichols,
T.A., Rogers, W.A., Fisk, A.D. and West, L.D. (2001), How old
are your participants? An investigation of age classifications
as reported in human factors, Proceedings of the Human Factors
and Ergonomics Society 45th Annual Meeting, 260-261.
|
| 55. |
Baldwin,
C.L. (2001), Impact of age-related hearing impairment on cognitive
task performance: Evidence for improving existing methodologies,
Proceedings of the Human Factors and Ergonomics Society 45th
Annual Meeting, 245-249.
|
| 56. |
Ziefle,
M. (2001), Aging, visual performance and eyestrain in different
screen technologies, Proceedings of the Human Factors and
Ergonomics Society 45th Annual Meeting, 262-266. |
|
| |
|
|
| The
Ergonomic Pragmatist |
| |
|
|
| |
|
Great list
Bob. But let me share a few ideas and concerns.
1. I agree
that 98% of browsers can show flash without a download. But without
usability training 98% of developers will use flash in ways that
makes the site worse.
2. Web applications
are different. But for most cases do NOT try to mimic a windows
applications. Users will expect to be in a browser and have the
back button work.
3. Give it
up Bob. It is too late to move the scroll bar to the left.
4. Be careful
about making decisions just because the users said they preferred
it. There may be hidden performance costs (as in #35 where redundant
links will take space that could be used for useful content). Also,
one of my favorite quotes of the year... "Because someone likes
something doesn't mean it will move merchandise." Carolyn Burke
- Sr. eCommerce Manager at Royal Bank
5. Obviously
testing with 5 users was a bad idea. But 100s will be impractical
for all but remote summative tests (which are much less valuable
then formative tests early in the design process). Be practical
and run formative tests with 12-30 subjects.
6. Automated
testing does let you run lots of users in remote locations. It works
well for summative testing. But for formative testing I recommend
in person studies where you can watch users, notice their reactions,
and talk freely about the design.
|
|
3-day
Annual User Interface Update Seminar
presented by Dr. Robert Bailey
Suggestions, comments,
questions?
HFI editors at
|
