Transcript TechDis: Accessibility and Usability Presentation

Accessibility of Web-based
and E-learning Materials
Dr. Simon Ball
E-mail:
[email protected]
www.techdis.ac.uk
E-learning: Accessibility and Usability
•
•
Accessibility:
– “can be easily and conveniently approached,
entered, and used by people with
disabilities…”
(US National Parks)
Usability:
– “is the quality of a system that makes it easy
to learn, easy to use, easy to remember,
error tolerant, and subjectively pleasing.”
(Jakob Nielsen – www.useit.com)
Universal Design
• Accessible web design does not require
special techniques or separate
resources for disabled students.
• Designing accessible resources results
in them being more usable for
everyone, regardless of disability or
browsing environment.
• This concept is known as ‘Universal
Design’
Design For All
• The EU term for Universal Design
• During 2002 the EU will support the creation
of a Network of Centres of Excellence, at
least one in each Member State, that will train
web designers and engineers in the principles
of Design-For-All
• European Institute for Design and Disability –
increases knowledge across EU about
barrier-free design
• www.design-for-all.org
NN Group: Quantitative Research
• Involved 60 people, all familiar with using the
Internet, and where applicable all
experienced at using the assistive devices
employed
– 20 screen reader users
– 20 screen magnifier users
– 20 people using no assistive technology
• All were set four simple tasks, and given 20
minutes per task to complete them
NN Group: Quantitative
ResearchTasks
• Fact-finding:
– find the average temperature in Dallas (no site
specified)
• Buy online:
– Janet Jackson’s latest CD from
www.target.com
• Information retrieval:
– take a bus in Chicago www.transitchicago.com
• Compare and contrast:
– find a specific kind of mutual fund on
www.schwab.com
NN Group: Major findings
Participants who used no assistive technology
were
• about six times more successful at
completing tasks than people using screen
readers
• three times more successful than people
using screen magnifiers
There was also a very close relationship
between success and satisfaction
NN Group: Completion Statistics
• No assistive technology users:
–7/10 completed, 1/10 ran out of time, 2/10 gave up
• Screen magnifier users:
–2/10 completed, 4/10 ran out of time, 4/10 gave up
• Screen reader users:
–1/10 completed, 5/10 ran out of time, 4/10 gave up
Mencap Research
• 11 users with learning difficulties
reviewed 30 popular web sites in August
2001. Users had varying levels of
familiarity with the Internet
• Asked to give scores on visual appeal,
clarity, navigation, is it obvious what’s
being provided, help and contact
details, is language understandable and
readable, presence of graphics / audio
to aid understanding
Mencap findings: top marks to
www.royalmail.com/access
Mencap: lowest marks to
www.bluewater.co.uk
So, where do we start?
• Web Accessibility Initiative
www.w3.org/WAI
• Web Content Accessibility Guidelines
www.w3.org/TR/WAI-WEBCONTENT/
• TechDis Seven Precepts
www.techdis.ac.uk/seven
• Read first and digest BEFORE doing
anything!
Some basic design tips - 1
Think about the technology being
used – some of your intended
audience may have old equipment
such as monochrome screens or
poor graphical capabilities, some
may be using screen readers,
screen magnifiers or mouthsticks
Some basic design tips - 2
Think about colour and visual
effects. Is the page clear in
greyscale? Do links change to a
less visible colour after use? Does
anything flash or move and if so is
there a capability to switch them off
at the start of the page?
Some basic design tips - 3
Organise materials in a simple and
logical order. The order of your
information may be obvious to you,
but will it make sense if read
linearly? Will it make sense to
someone with perceptual
difficulties?
Some basic design tips - 4
Present a clear organisational
structure. The first page should be
no more than an overview, with
clear pointers to the remaining
material and each subsequent
page’s content.
Some basic design tips - 5
Each page must make sense in its
own right. Include links back to the
start page and a brief overview of
where the viewer is in the schema.
Put this information at the end of
each page (to avoid irritating
screen reader users)
Some basic design tips - 6
• Include meaningful ‘alt’ tags for all
images
• Caption all audio and video
• Make links sensible (not just ‘click
here’)
How not to do it (in plain English)
Some easy-to-understand tips pages:
– www.earth.com/bad-style/
– www.tuxedo.org/~esr/html-hell.html
– www.ratz.com/featuresbad.html
So how can I be sure…..
• Checking tools – there are many. Use a
good one! Try:
• A-Prompt:
– Aprompt.snow.utoronto.ca
• The Wave:
– www.temple.edu/inst_disabilities/piat/wave/
• TechDis:
– www.techdis.ac.uk/seven
Bobby?
• Many web designers still favour
Bobby despite price
• Being Bobby compliant gives you a
logo for your page
• It is hard to use and unhelpful
• Bobby compliance is not the goal
• Go for WAI Level 2 instead