Transcript Powerpoint

Usability and accessibility: are
they two sides of the same coin
and does it matter anyway?
Penny Garrod
UKOLN
University of Bath
Bath, BA2 7AY
Email
[email protected]
URL
http://www.ukoln.ac.uk/
UKOLN is supported by:
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Contents of session
1. Warm up exercise: (10 minutes)
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What do we mean by Accessibility?
What do we mean by Usability?
Do we need to differentiate?
2. Discussion: which guidelines?:
RNIB/NLB; W3C; Government guidelines; Ch.14
of Resouce’s Manual of Best Practice (VIPs) etc.
3. Evaluation: Tools for testing: the Wave;
Bobby; Lynx Viewer….
4. Advice from other organisations and
usability gurus:e.g. Microsoft; HE sector;
Jakob Nielsen.
5. Conclusions and list of resources
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Accessibility v. Usability
Accessibility
•Technical guidelines
•Adapting a visual medium
so that everyone can use it
• accessible to wide range
of disabilities e.g. dyslexia;
colour blindness; sensory
and physical impairment; not
all disablities are visible
•Also benefits non-disabled
users e.g hands busy
situations
Usability
“A measure of how easy is it for
users to find their way around
your website”
(APLAWS desk top study)
• can task be effectively carried
out and information found?
• User testing required
• involve users from outset;
design in stages – testevaluate-improve cycle
Universal accessibility: serving largest possible
audience using broadest range of systems; needs of
users with disabilities considered
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Guidelines and advice
What have you used and
found useful?
RNIB
A-AAA
conformance
What do OeE advise?
“Be both acessible and usable”
Enable citizens to find what
they want and what they’re
interested in.
Legal imperative: DDA; EC
resolution (E-Europe 2002 –
adopt WAI guidelines at all
levels of government)
UK Government policy = Level
‘A’ WAI conformance (likely to be
AA soon)
OeE website guidelines
–framework for local
government; Illustrated
Handbook for web
management teams
Best Practice
manual
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Guidelines and advice from OeE
•Content: ask users to test it and find out if they can
find, understand and use all your website offers
•Advice from user research – use plain language;
short, scannable text with subheads; bulleted lists
•PDF documents – provide alternatives e.g. HTML
and plain text
• Branding – consistent look and feel throughout helps
users; design features to give local, non-government feel
• Avoid reproducing documents aimed at internal
audience on public website
•See section 2.4 of illustrated handbook:
building in universal accessibility; + section 2.5 on
browsers; long checklist provided
•Special needs: technophobic; socially excluded;
older people; non-english speakers
• use W3C accessibility guidelines and quick
tips; minimum ‘A’ (priority 1 items) rating required
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Guidance from RNIB
Blind people use IE + screen reader + keyboard
(tab+enter keys) - not mouse
Personalised settings – people’s needs change
from day to day so not good idea to set these
Plug-ins: need installing, seen as barrier to users;
problem with silent pages (images only); Flash
software not liked by RNIB (there are ‘accessibility
kits’ available from Macromedia)
Forms – these should work in linear style for
screen readers
Images – ‘alt-text’ tag is essential; functional
description or “ ” null text for non functional images
Do not recommend separate text only site
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Other sources of advice
from Resource’s Best Practice Manual ch. 14
•Stick to the official W3C web content accessibility guidelines
•Use Lynx Viewer to see how page looks with text only and
how it will be interpreted by screen reader
•Use W3C HTML validator service to check code against
version used
•Use cascading style sheets to separate content from display
structure
Techdis: http://www.techdis.ac.uk/ (good resources aimed at
HE but generally useful)
APLAWS – http://www.aplaws.org.uk “a desktop study of
usability issues for web site design” – lists key resources +
useful info on CSS, frames, screen resolutions etc.
Trace center (University of Wisconsin- Madison, USA)
Designing more usable websites:
http://www.trace.wisc.edu/world/web/index.html
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Evaluation: Tools for testing
the Wave – from Pennsylvania Institute on Disabilities
(free)
Bobby - from Watchfire (test one page free – pay for
downloadable version to test entire site as batch
c.$99)
Lynx Viewer (free)
Vischeck (from Stanford University) – simulates colour
blindness and Daltonize which corrects images for
colourblind viewers (both on Vischeck site)
Questions
How useful are these tools?
How reliable are they?
Do they take too much time and effort to use and
interpret results?
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Web-based tools: the WAVE
Pennsylvania’s Initiative on Assistive Technology
from:
http://www.temple.edu/inst_disabilities/piat/wave
 Wave can’t tell you if page is accessible - no
automated tool can
 adds icons and text to help you judge if page is
accessible; provides information to help you
exercise judgment
 downloadable tutorial
 Incorporates browser check e.g.
– “I'm using a recent browser” (Internet Explorer 5,
Navigator 6, Opera 4 or higher)
– Analyze No-Frame Version
 Downloadable ‘Wave’ button (like Google)
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Wave analysis of Hampshire’s
entry point
http://www.hants.gov.uk
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http://bobby.watchfire.com/
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Bobby: Browser compatibility test
http://bobby.watchfire.com/bobby/html/en/advanced.jsp
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Lynx Viewer
http://www.delorie.com/web/lynxview.
html
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Saga home page: www.saga.co.uk/
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Saga site viewed with Lynx Viewer
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Vischeck: www.vischeck.com/
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Advice from other organisations
and gurus
Jakob Nielsen (2000) Designing Web
usability:the practice of simplicity.
Indianapolis,Ind.:New Riders.
His web site: http://www.useit.com/
 the book: useful tips e.g. content should account for 50%
of page- preferably 80%; navigation <20%; use resolution
independent design (use percentages of available space) as
most people still use small monitors (800x600)
 suggests you identify top 3 reasons why people come to
your site; simple things should be simple to do remember
users are goal-driven
Website very useful resource: re Flash usability; age
related stuff; e-commerce usability etc.
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Where else can I find advice?
Microsoft: http://www.microsoft.com/enable/
Lists assistive technology for different categories of disability; tutorials
for Microsoft users e.g. windows users with visual impairment;
adjusting computers for mobility needs.
Techdis: http://www.techdis.ac.uk/ designed for HE community but
includes database of 2,500 items of assistive technology – applies to all
learners
How People with disabilities use the web (W3C)
http://www.w3.org/WAI/EO/Drafts/PWD-Use-Web/Overview.html
**APLAWS – A desktop study of usability issues for web site design:
www.aplaws.org.uk
- concise, clear, collation of much of what has been written to help
local authorities avoid common mistakes;
+ lists of resources
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W3C Ten quick tips for accessible
websites
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www.ukonline.gov.uk - normal view
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Easy access version of UKonline
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Conclusions? What do you
think?
'image: www.freeimages.co.uk'
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