Users with Special Needs: Age, Lower Literacy, Disabilities

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Users with Special Needs Age, Lower Literacy,
Disabilities

• Kathryn Summers
• 2004

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Older users

• Older users comprise 13 of US population 34.5
  million in 2001 (perhaps 10 million in 2050).
• About 13-16 of seniors used the internet in
  2001. Will grow to 51 by 2015 as boomers retire.
• Older users are often less experienced web users,
  and are likely to face some physical and
  cognitive impairment. (58 or 20 million suffer
  chronic joint pain.)

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Older users and Web usability

• Usability testing shows that age effects are
  smallest for tasks that depend on knowledge and
  experience. They are largest for tasks that
  depend on speed.
• Older users have trouble finding informationthey
  do not seem to perceive information scent as
  strongly as younger users.

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Older usersCognitive issues

• Some older users face cognitive impairments as
  they age
• A reduced ability to divide attention between
  tasks, slower and more laborious switching of
  attention between tasks
• Decreased working memory capacity
• Decreased visual search performance
• Increased time to access long-term memory

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Older usersEmotional issues

• Older users are sometimes more vulnerable to
  frustration, anxiety, and self-blame.
• Because many Web sites are less usable for older
  users, such users may also experience "learned
  failure." Previous bad experiences damage users'
  confidence that the information is available or
  that they can find information. When faced with
  difficulties, such users may give up quickly.

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Older usersCoping strategies

• Thorough readingmultiple studies show that older
  users are more likely to carefully read all info
  on a page before moving on
• Cautious clickinga reluctance to click on links
  unless they are sure they have found what they
  want
• Seeking help from peers or family members

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Older users--Vision issues

• Many older users experience some degree of vision
  impairment
• Reduced acuity
• Reduced color perception (especially the
  green/blue/violet range)
• Reduced contrast discrimination
• Increased sensitivity to glare (consider using
  off-white backgrounds rather than pure white)
• Decreased visual search performance
• Reduced focusing abilitydifficulty following
  objects in motion
• Reduced field of view

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Older usersMotor Issues

• Movements may take longer for older users. Both
  typing and moving the mouse take more time and
  effort. In testing, tasks that required 3 or more
  clicks were experienced as time-consuming and
  difficult for older users.
• Older users experience dramatically reduced time
  on task and reduced error rate if Web designers
  use "sticky" links (30 reduction of the cursor's
  gain ratio as you near the link gain ratio
  returns to normal after passing the link).
  (Georgia Institute of Technology study, 1997).

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Lower-literacy users

• Its harder for many American adults to read than
  you might think. The National Adult Literacy
  Survey (2003) by the U.S. Department of Education
  estimates that
• Up to 23 of the US population is functionally
  illiterate
• Nearly 50 of US adults, or 90 million people,
  read at the 8th grade level or below
• Most Web sites are written at the 12th grade
  level or above.

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Lower literacy users struggle with

• Using search engines to find desired content
• Navigating to desired information on individual
  sites
• Reading content whenor ifthey find it

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Navigating through page contentreading every word

• Reading is hard for lower-literacy users. It
  takes a great deal of concentration and effort.
  Most lower-literacy users cant grasp the
  structure of the page at a glance by reading
  headings and subheadings. Some lower-literacy
  users compensate by reading every word on the
  page so that they dont miss the answer.
• Similar thorough reading has been reported for
  older users and less Web-experienced users.

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Skipping chunks of text

• When confronted by long, dense pages of text,
  some lower-literacy users simply skip chunks of
  text. Ironically, such users would sometimes end
  up skipping over the content they wantedeven if
  the target content was appropriately signaled by
  a heading, a well-chunked paragraph, or a
  bulleted list.
• This skipping was clearly not the same as the
  scanning behaviors employed by more literate
  userson longer pages with multiple paragraphs,
  the lower-literacy users would often skip right
  over headings and lists in order to land in the
  middle of a paragraph.

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Triggers for skipping

• Skipping seemed to be triggered most often by
• Long paragraphs of dense text
• Long sentences with complex syntax
• Long pages requiring scrolling
• Numbers contained in the text
• Difficult, long, or unfamiliar words
• Parenthetical text

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Hopping from link to link

• Some low-literacy users tried to minimize the
  amount of reading they would have to do by
  focusing on finding links instead of reading
  content. These users skipped from link to link
  throughout the site, sometimes ignoring page
  content completely. Such users had very low rates
  of task success.
• When asked, users said they were hoping to arrive
  at more focused information. Users who relied on
  this strategy sometimes landed on pages with
  their desired content but did not see it.

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"Satisficing" quickly

• Because looking for additional information
  requires more reading, lower-literacy users tend
  to decide they have enough information relatively
  soon.
• This frequently meant settling for answers that
  were incomplete or misleadingly vague. Marketing
  speak was particularly difficult for such readers
  to process.
• Clearly, the most important information needs to
  appear first in its contextwhether on a page, in
  a paragraph, or in a list.

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Users with Vision Loss

• Users with vision loss typically rely on
  screenreaders to access and navigate the Web.
• Screenreaders cannot read graphics they read the
  associated ALT text. To optimize pages for users
  with reduced vision, minimize the use of
  graphics. All graphics should be accompanied by
  simple ALT text that makes sense without seeing
  the image, and a LONGDESC description that
  thoroughly describes the image. Or refer users to
  an alternate source for the information contained
  in the graphic.
• Screen readers can be set to read only the links
  on a page rather than the content. Visually
  impaired users have a higher rate of task success
  when the number of links on a page is limited.

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Navigating through Page Content

• A large research study of visually impaired users
  conducted by the Nielsen Norman Group observed
  several of the same strategies for navigating
  through page content that our study observed in
  lower-literacy users.
• Thorough reading
• Link hopping
• Skipping

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Reading or listening to every word

• Some users who depend on assistive technology
  know that it is easy to miss key content or key
  links, so they carefully listen to all the
  content on every page before choosing any links
  or performing any actions.

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Hopping from link to link

• Some users who depend on screen readers set the
  screen reader to read only the links on a page.
  Such users may end up skipping from link to link
  within the site, and may not know when they have
  arrived at a page with desired content.
• Task success can be increased for these users by
  minimizing the number of links on each page and
  including a page headline that is read first by a
  screen reader, so that users can immediately
  identify page content.

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Skipping chunks of text

• Because listening to a page or moving through a
  magnified page can be agonizingly slow, some
  users with vision loss will attempt to skip
  ahead. But because they cannot see what they are
  skipping, such users will sometimes skip over the
  content or link that they want.

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Triggers for skipping

• Skipping seemed to be triggered most often by
• Long strings of parameter descriptions associated
  with page formatting, such as scripting, tables
  used to format content, or long lists of mostly
  irrelevant links
• Long paragraphs of dense text
• Long pages requiring scrolling
• Parenthetical text

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Conclusion

• Look for design solutions that meet the needs of
  diverse user groups.
• Do actual testing with representative users.
  There is no substitute for watching real users do
  real tasks.
• Learn the cognitive and biological science behind
  the behaviors you seeit facilitates persuasion.