Website usability

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Website usability

• Surprising findings from the research

Marianne W. Zawitz
Bureau of Justice Statistics
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What is usability?

• The measure of the quality of the user
  experience when interacting with something --
  whether a traditional software application, or
  any other device the user can operate in some way
  or another.

Jakob Nielsen Devhead, www.zdnet.com, 9/29/98
Bureau of Justice Statistics
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Usability is measured by

• Ease of learning
• Efficiency of use
• Memorability
• Error frequency and severity
• Subjective satisfaction

Bureau of Justice Statistics
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The usability profession

• From cognitive psychology
• Focused on Human Computer Interface (HCI)
• Initial work was testing software interfaces

Bureau of Justice Statistics
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Most sites fail on usability

• Internally focused
• Mirror the organization structure
• Designed for the boss
• Do not involve users in development

Bureau of Justice Statistics
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Why do we have usability problems?

• Technical make it work
• Artistic/graphics make it pretty
• Content put everything up there
• Program highlight my material
• None of them are focused on the users.

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What are the benefits of including usability in
web design?

• Success costs less - savings from internet
  transactions will never be realized unless sites
  are usable
• If users cant find it, it is not there
• Bad usability equals no customers
• Usable sites result in fewer customer inquiries
  which equals less staff time

Bureau of Justice Statistics
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Usability techniques have been applied to the web

• Designing Web Usability, Jakob Nielsen, 2000
• Dont Make Me Think, Steve Krug 2000
• Keith Instones Usableweb (http//usableweb.com/)
• usability.gov
• many more in handout

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Users loose patience with sites where the purpose
of the site is not clear

• The home page should clearly indicate what the
  site is about
• Try to get the most important elements that
  convey the purpose in the top left section of the
  home page

Bureau of Justice Statistics
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Need for speed

• Traditional human factors research shows users
  loose interest after 5 seconds
• Due to slowness of the web, internet users are
  more patient - 15 seconds
• Rule of thumb is to limit a page to 35 - 50 KB
  (Sum of all files that make up the page)

Bureau of Justice Statistics
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Tips for speeding up your site

• Graphics
• Avoid unnecessary graphics particularly image
  maps
• Reduce the number of colors
• Use width and height specifications
• Break up extremely large pages
• Make database queries quick
• Avoid Flash intros

Bureau of Justice Statistics
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Users read differently on the web

• Users scan content
• In a study by Nielsen and Morkes -
• 79 of users tested always scanned new pages
• 16 read word-by-word
• On screen reading is 25 slower than on paper

Bureau of Justice Statistics
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Writing for the web involves

• Chunking
• Inverted pyramid style with the conclusions
  first
• Meaningful subheadings and keywords
• Bulleted lists
• One idea per paragraph
• Half the word count than conventional writing

Bureau of Justice Statistics
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To facilitate scanning, make sure the text is
legible

• Text and background must have high contrast
• Avoid all caps
• Avoid text that is too small

Bureau of Justice Statistics
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Terminology

• Users have difficulty with technical or domain
  specific terms
• Users are unsure of where categories may lead
  especially if they are cutsey
• Users hate marketese

Bureau of Justice Statistics
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Users will scroll vertically

• Need a reason to go down the page
• The fold is not a constant
• Users were just as likely to have their first
  click below the fold as above the fold

Bureau of Justice Statistics
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Users do not like to scroll horizontally

• Users expect all the content to be displayed
  within the browser window
• Many web pages are designed for larger monitors
  but not all users have large monitors
• Many users choose not to maximize their browser
  window

Bureau of Justice Statistics
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To avoid horizontal scrolling, use resolution
independent pages

• Never specify tables, frames, or other design
  elements in fixed pixels - Use percentages
• If you must specify some elements in fixed
  pixels, use a total width that will fit a small
  monitor - 640 X 480

Bureau of Justice Statistics
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Animation is uniformly annoying

• Users will ignore animated objects thinking they
  are ads
• Many users will scroll down to avoid animations
• Some users turn off animation in their browsers

Bureau of Justice Statistics
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Organization

• Users have no patience with disorganized sites
• In the Breadth Vs. Depth Battle, users prefer
  breadth (few clicks to content)

Bureau of Justice Statistics
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Users need to know where they are, but seldom do

• Users dont have a perceived mental model like
  they do with software
• Users tend to go forward, but the back button is
  the most frequently used navigation function
• Using the same navigation on every page confuses
  people

Bureau of Justice Statistics
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Build navigation on user behavior

• Never break the back button
• Avoid shell structures with generic navigation
  on every page
• Differences in navigation based on context are
  helpful as navigation needs to fit with content
• Indications of where you are help

Bureau of Justice Statistics
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Crumbs are a very useful device to show users
where they are

• Homegt Products gtPublicationsgt Order

Bureau of Justice Statistics
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Navigation bars

• Users do better with navigation bars at the top
  or bottom rather than the side
• Duplicated links on the left and bottom confuse
  people
• Clues that you were on a particular page on the
  nav bar are very helpful
• No more than 20 of the page on a destination
  page should be navigation

Bureau of Justice Statistics
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Other features cause users to get lost

• Inconsistent look and feel
• No way to get back to home
• Opening a new window
• breaks the back button
• Frames
• URLs stop working
• Difficult to bookmark
• Can trap users within frameset

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Pop-ups must die

• Something users didnt ask for
• Usually ads
• Break the back button

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Other navigation devices

• Users like Tables of Contents with sub-items to
  take them directly to content
• Site maps are helpful but not as good a Tables
  on Contents
• FAQs frustrate users seeking specific information

Bureau of Justice Statistics
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Links for navigation

• The number of links is negatively correlated
  with success in finding information
• Users try to rule out links that are not going
  the right place
• Links with short titles do not work

Bureau of Justice Statistics
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Users want to know what they are going to get
when they link

• 7 - 11 word descriptions are most useful
• Anchors should be 3 - 4 words
• Words must be informative to be useful
• Use words users know avoid ambiguity
• Make the link and the destination title the same

Bureau of Justice Statistics
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Graphics do not work well as links

• No indication that they are links
• Visited links do not change color
• If they are buttons they may not be big enough
  for the user to determine they are links

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Users get confused when link colors are not
standard

• Unvisited links should be blue
• Visited links should be reddish or purple
• Using standard colors means users dont have to
  learn anything new

Bureau of Justice Statistics
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Embedded links are harder to follow than separate
links

• Due to the way users scan the page
• Use embedded links for contextual information
  rather than for navigation to information
• Dont underline nonlink material

Bureau of Justice Statistics
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Searching

• About one third of the users in UIEs study
  always went to the search facility
• Users were often confused about what was covered
  by the search
• Search results are often very confusing or
  lacked information to tell the user what the
  results linked to

Bureau of Justice Statistics
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To facilitate searching -

• Put the scope of the search with the search
  window Offer users a way to narrow the search
• Make sure that each html page is properly titled
  since that is what shows up in the search results
• Compensate for user error

Bureau of Justice Statistics
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Reliability of information

• Users want too know who is presenting
  information
• Some users prefer to see the date of the last
  update
• Reputation managers are contributing to ensuring
  the reliability of information(eBay, Epinions,
  Google, Go)

Bureau of Justice Statistics
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Accessibility is also a usability issue

• Many users --
• have disabilities
• are from foreign countries
• connect on slow modems or use older equipment and
  software

Bureau of Justice Statistics
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Accessible sites are good business

• Increase customer base
• 1 in 5 Americans have some disability
• More expected as the country ages
• Available to all citizens
• New technology will demand similar standards
• Wireless devices - phones
• PDAs

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Universally accessible sites --

• Do not use proprietary tags
• Provide text only alternatives
• Include descriptions of all substantive graphics
• Provide text descriptions of all audio and video
• Provide alternatives to forms
• Provide downloadable files in formats most
  visitors can use

Bureau of Justice Statistics
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Accessibility resources

• W3C Web Content Accessibility Guidelines
• Access Board 508 site
• Unified Web Site Accessibility Guidelines - TRACE
  Center
• GSAs Universal Information Access on the WWW

Bureau of Justice Statistics