Transcript UCD tutorial

eTEN Tenuta support action
Usability and accessibility of
educational web sites
Nigel Bevan
[email protected]
University of York
UK
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How Usable are current systems ?
 UK Passport Office
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New software for issuing passports took operators twice as long
Caused delays of up to 3 months in obtaining a passport
Huge cost of additional clerical staff
 E-commerce web sites
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User success in purchasing ranges from 25%-42%
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ISO 9241-11 Guidance on Usability
 Usability is more than the user interface
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Usability: The extent to which a product can be used by specified users to
achieve specified goals with effectiveness, efficiency and satisfaction in a
specified context of use
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Effectiveness: The accuracy and completeness with which users achieve
specified goals.
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Efficiency: The resources expended in relation to the accuracy and
completeness with which users achieve goals.
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Satisfaction: The comfort and acceptability of use
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Why this matters
 Usability is about meeting user needs
 Two types of educational user: student and instructor
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Effective: success in achieving navigational and educational goals
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Efficient: can be completed in an acceptable amount of time
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Satisfied: willingness to use the system
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How do you achieve usability?
 ISO 13407
Human-centred design process for interactive systems
 Principles of user-centred design
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understand the users and their tasks
evaluate prototypes with users
iterative development
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Understand users and the context of use
 The usability of a product is affected not only by the
features of the product itself but also by its Context of Use
 Context is the characteristics of:
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the users of the product
any disabilities
the tasks they carry out
the technical, organisational
and physical environment
in which the product is
used
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Why is usability important?
 Focus on user needs
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reduce development times
lmprove effectiveness
simpler interface, fewer user errors
 Reduce development costs by:
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Producing a product that has only relevant functionality
Detecting and fixing usability problems early in the development
process
Minimizing or eliminating the need for documentation and training
Reducing the risk of product failure
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Accessibility
 Default industry “standard” is the Web Content Accessibility
Guidelines (WCAG)
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Developed by the Web Accessibility Initiative (WAI) of the World Wide Web
Consortium (W3C)
 14 Guidelines (e.g. “Provide equivalent alternatives to auditory and
visual content”)
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65 checkpoints
 WCAG1 is the basis of a number of other accessibility guidelines
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eGIF document of the UK government,
Section 508 of the Rehabilitation Act (USA),
EU Action Plans (e.g. eEurope2002, 2005)
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Priorities
 Checkpoints are grouped into three levels of importance (= Priority
levels in WCAG speak)
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Priority 1 (level A accessible): A Web content developer must satisfy this
checkpoint. Otherwise, one or more groups will find it impossible to access
information in the document.
Priority 2 (level AA accessible): A Web content developer should satisfy this
checkpoint. Otherwise, one or more groups will find it difficult to access
information in the document.
Priority 3 (level AAA accessible): A Web content developer may address this
checkpoint. Otherwise, one or more groups will find it somewhat difficult to
access information in the document.
 But WCAG accessible does not necessarily mean usable!
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Tools
 WAI recommends doing manual checks for accessibility and using 2
general tools on a selection of pages from a website.
 A particularly useful meta-tool is the Web Accessibility Toolbar
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www.visionaustralia.org.au/ais/toolbar
 An accessibility audit of about 30 pages of a large website with the
Toolbar takes about 30 person hours of work (about 80 individual
checks per page)
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Main accessibility issues
A UK study showed that 80% of accessibility problems are
covered by 10 WCAG1 checkpoints
1. Provide text equivalents for non-text elements
2. Ensure that foreground and background colour combinations
provide sufficient contrast when viewed by someone having color
deficits or when viewed on a black and while screen
3. Ensure that pages are usable when scripts, applets or other
programmatic objects are turned off or not supported. If this is not
possible, provide equivalent information on an alternative
accessible page.
4. Avoid movement in pages (until user agents allow users to freeze
moving content)
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Main issues continued
5. Do not cause pop-ups or other windows to appear and do not
change the current window without informing the user (until user
agents allow users to turn off spawned windows).
6. Divide large blocks of information into more manageable groups
where natural and appropriate.
7. Clearly identify the target of each link.
8. User the clearest and simplest language appropriate for a site’s
content.
9. Ensure that text size values are relative rather than absolute.
10. Use navigational mechanisms in a consistent manner.
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Evaluation with users
 Essential to observe users trying to use your system
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Demonstration is not enough!
 Create a typical usage situation
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Ask the user to carry out their tasks without any assistance and to think aloud
Do they understand what to do?
Do they follow the intended sequence?
Are their problems fort users with disabilities?
 If possible test at least 5 users
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But any better than none!
 One user test of an eTEN project
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“It is so longwinded I would never use it in a million years!”
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 www.usability.gov/pdfs
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Free download
$35 book
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7. Navigation
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10. Links
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10. Links
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10. Links
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12. Lists
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Tenuta Support for eTEN projects
 Training courses for usability and accessibility
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Genoa, 6 February
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Madrid, 2 days in mid April
 On-site support for eTEN projects to review their e-solutions
 More information: www.etenuta.org
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