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Website usability
Surprising findings from the research
Bureau of Justice Statistics
Marianne W. Zawitz
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.”
Bureau of Justice Statistics
Jakob Nielsen Devhead, www.zdnet.com, 9/29/98
Usability is measured by —
Ease of learning Efficiency of use Memorability Error frequency and severity Subjective satisfaction
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The usability profession —
From cognitive psychology
Focused on Human Computer Interface (HCI)
Initial work was testing software interfaces
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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
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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.
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 can’t find it, it is not thereBad usability equals no customersUsable sites result in fewer customer
inquiries which equals less staff time
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Usability techniques have been applied to the webDesigning Web Usability, Jakob
Nielsen, 2000Don’t Make Me Think, Steve Krug 2000Keith Instone’s Usableweb
(http://usableweb.com/)usability.gov many more in handout
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
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Need for speedTraditional 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)
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
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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
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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
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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
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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”
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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
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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
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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
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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
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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)
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Users need to know where they are, but seldom do
Users don’t 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
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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
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Crumbs are a very useful device to show users where they are
Home> Products >Publications> Order
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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
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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 URL’s stop working Difficult to bookmark Can trap users within frameset
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Pop-ups must die
Something users didn’t 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
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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
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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
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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 don’t have to learn anything new
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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
Don’t underline nonlink material
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Searching About one third of the users in UIE’s 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
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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
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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)
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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
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Accessible sites are “good business”Increase customer base
1 in 5 Americans have some disabilityMore expected as the country agesAvailable to all citizens
New technology will demand similar standardsWireless devices - phonesPDAs
Universally accessible sites --Do not use proprietary tagsProvide text only alternatives Include descriptions of all substantive graphicsProvide text descriptions of all audio and videoProvide alternatives to formsProvide downloadable files in formats most
visitors can use
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Accessibility resourcesW3C Web Content Accessibility
Guidelines Access Board 508 siteUnified Web Site Accessibility
Guidelines - TRACE CenterGSA’s Universal Information Access on
the WWW
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