Date post: | 28-Dec-2015 |
Category: |
Documents |
Upload: | cassandra-hall |
View: | 218 times |
Download: | 0 times |
• SCET MSc EC/ECA © Alan Woolrych 2001
COMM1P
9
IntroductionIntroduction
• Accessibility• “Making Content Available to All”
• Who are “all”?
• SCET MSc EC/ECA © Alan Woolrych 2001
COMM1P
9
• Design Assumptions• Sight
• Manual Dexterity
• Hand-Eye Coordination
IntroductionIntroduction
• SCET MSc EC/ECA © Alan Woolrych 2001
COMM1P
9
• They may not be able to see, hear, move, or may not be able to process some types of information easily or at all
• They may have difficulty reading or comprehending text
• They may not have or be able to use a keyboard or mouse
• They may have a text-only screen, a small screen, or a slow Internet connection
Lack of Capabilities 1Lack of Capabilities 1
• SCET MSc EC/ECA © Alan Woolrych 2001
COMM1P
9
Lack of Capabilities 2Lack of Capabilities 2
• They may not speak or understand fluently the language in which the document is written
• They may be in a situation where their eyes, ears, or hands are busy or interfered with (e.g., driving to work, working in a loud environment, etc.)
• They may have an early version of a browser, a different browser entirely, a voice browser, or a different operating system
• SCET MSc EC/ECA © Alan Woolrych 2001
COMM1P
9
• 8.5 Million disabled people in UK
• 20% working population are disabled
• 17million adults with literacy problems
• 1 million adults with learning difficulties
• 1.7 million people unable to read standard print– Source: Disability Rights Commission -
Disability Briefing Briefing: February 2001
Some Statistics (UK)Some Statistics (UK)
• SCET MSc EC/ECA © Alan Woolrych 2001
COMM1P
9
• 9.6% of population with severe disability
• 9.9% of population with non-severe disability
• 19.5% of population with some degree of disability or,
• Nearly 49 million people
Some Statistics (USA)Some Statistics (USA)
• SCET MSc EC/ECA © Alan Woolrych 2001
COMM1P
9
More Recently (IBM)More Recently (IBM)
• Over 8 million Americans have visual impairments.
• 2.7 million Americans have speech impairments.
• 13.5 million Americans consider themselves visually impaired to some degree.
• 22 million Americans are deaf or hard-of-hearing.
• Nearly 3 million Americans are colour-blind.
• SCET MSc EC/ECA © Alan Woolrych 2001
COMM1P
9
• Dyslexia affects over 40 million Americans.
• 4.6 million Americans use Assistive Technology Devices for hearing impairments.
• 500,000 visually impaired Americans use Assistive Technology Devices.
More Recently (IBM)More Recently (IBM)
• SCET MSc EC/ECA © Alan Woolrych 2001
COMM1P
9
LegislationLegislation
• The Disability Discrimination Act 1995 (UK)• Does apply to IT
• Lot of grey areas (like most laws)
• Lacks Enforcement
• SCET MSc EC/ECA © Alan Woolrych 2001
COMM1P
9
Technology AidsTechnology Aids
• Screen Reader
• Aural feedback
• Visual signalling for audio
• SCET MSc EC/ECA © Alan Woolrych 2001
COMM1P
9
1. Provide equivalent alternatives to auditory and visual content
1. text equivalent for non-text content (e.g. alt tag for images)
2. vice-versa...non-text equivalent for text (beneficial for non readers)
Accessibility Guidelines Accessibility Guidelines (W3C)(W3C)
• SCET MSc EC/ECA © Alan Woolrych 2001
COMM1P
9
• Don’t rely on colour alone• text and graphics should be
understandable even when viewed without colour
• e.g. colour deficiencies, monochrome displays
Accessibility Guidelines Accessibility Guidelines (W3C)(W3C)
• SCET MSc EC/ECA © Alan Woolrych 2001
COMM1P
9
• Use markup and style sheets and do so properly• e.g., using a table for presentation effect
• difficulties using specialised software, such as organisation of the page and navigation
• But don’t sacrifice appropriate markup!
Accessibility Guidelines Accessibility Guidelines (W3C)(W3C)
• SCET MSc EC/ECA © Alan Woolrych 2001
COMM1P
9
• Clarify natural language usage• Use markup that facilitates pronunciation
or interpretation of abbreviated or foreign text
• natural language markup allows:• search engines to find key words and
identify documents in a desired language, improves readability of the Web for all people, including those with specific difficulties
Accessibility Guidelines Accessibility Guidelines (W3C)(W3C)
• SCET MSc EC/ECA © Alan Woolrych 2001
COMM1P
9
• Create tables that transform gracefully• Tables for any use also present special
problems to users of screen readers
Accessibility Guidelines Accessibility Guidelines (W3C)(W3C)
• SCET MSc EC/ECA © Alan Woolrych 2001
COMM1P
9
Accessibility Guidelines Accessibility Guidelines (W3C)(W3C)
• Ensure that pages featuring new technologies transform gracefully• Use new technologies BUT..
• Make sure pages work in older browsers, and when users choose to turn features off
• e.g that pages are usable when scripts, applets etc. are turned off or unsupported
• SCET MSc EC/ECA © Alan Woolrych 2001
COMM1P
9
• Ensure user control of time-sensitive content changes
• Allow user control over moving, blinking, scrolling objects…paused or stopped
Accessibility Guidelines Accessibility Guidelines (W3C)(W3C)
• SCET MSc EC/ECA © Alan Woolrych 2001
COMM1P
9
• Provide context and orientation information
• help users understand complex pages – Especially users with cognitive or
visual disabilities
– Helps all users
Accessibility Guidelines Accessibility Guidelines (W3C)(W3C)
• SCET MSc EC/ECA © Alan Woolrych 2001
COMM1P
9
13.Provide clear navigation mechanisms
13.Be consistent and..13.Clearly identify the target of each
link
14."Information about version 4.3" instead of "click here".
Accessibility Guidelines Accessibility Guidelines (W3C)(W3C)
• SCET MSc EC/ECA © Alan Woolrych 2001
COMM1P
9
• Ensure that documents are clear and simple
• Clarity + Simplicity = Understanding
Accessibility Guidelines Accessibility Guidelines (W3C)(W3C)
• SCET MSc EC/ECA © Alan Woolrych 2001
COMM1P
9
A Design IssueA Design Issue
“Designing better interfaces for people with special needs will almost inevitably lead to better interfaces for all”
Alistair D N Edwards