The document discusses accessibility in web design. It defines accessibility as designing products, devices, and environments to be usable by people with disabilities through both direct and indirect access via assistive technologies. It notes that accessibility benefits all users by working for those with slow connections or small devices. The document outlines how up to 20% of people have disabilities that impact web use, such as visual, hearing, motor and cognitive impairments, and discusses common barriers to accessibility like lack of captioning for deaf users or exclusive keyboard navigation. It provides resources on web accessibility standards and initiatives.

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INTERACTIVE SYSTEMS USABILITY DESIGN
Roberto DADDA e Paolo NEGRI

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Accessibility
In a nutshell

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Accessibility definition
• Accessibility in the sense considered here refers to
the design of products, devices, services, or
environments so as to be usable by people
with disabilities. The concept of accessible design and
practice of accessible development ensures both
"direct access" (i.e. unassisted) and "indirect access"
meaning compatibility with a person's assistive
technology (for example, computer screen readers).
• Not for disabled only, good for slow network
connection, small smartphone…

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Accessibility
• The internet is a place of equality. It can give us power and choice at the
same level if accessible.
• Tim Berners-Lee (founder of WWW) says the power of the web is in its
universality: access by everyone regardless of disability is its essential
aspect.
• Inclusion and supporting the underserved populations.
• Federal Section 508 standards – ADA law – Legge stanca

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Accessibility is…
• Accessibility is not…
• Text-only pages
• Separate accessible versions (except in multimedia)
• Boring
• Difficult
• Accessibility is…
• Accessibility is about building web pages that can be navigated and read by
everyone, regardless of disability, location, experience or technology.

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Web Accessibility
• Up to 20% of Americans have some kind of disability.
• The major kinds that affect web use include:
• Visual – blind, low vision, color-blind
• Hearing – deafness
• Motor – inability to use a mouse, slow response time, limited fine motor
• Cognitive – includes learning disabilities, unable to focus

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Barriers to Accessibility
• Visual: Screen readers, read web page content aloud for people who
have low or no vision.
• Deaf: Need captioning for sound.
• Motor: People who don’t have use of their arms or hands sometimes
navigate the web via the keyboard, hitting keys with a stick in their
mouths.
Requires site design that allows for exclusive keyboard navigation…(try
getting around a web page using just the keyboard, without
using a mouse.)

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Link to the document

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Resources on accessibility
Web accessibility initiative, W3C WAI
theaccessibilityresourcecenter

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Usability
Roberto DADDA
roberto@dadda.it
www.dadda.it
Skype, Facebook e Twitter robertodadda