Transcript 14.1 Introduction - Internet Entrepreneurship

Chapter 14, Accessibility
Outline
14.1
14.2
14.3
14.4
14.5
14.6
Introduction
Web Accessibility
Web Accessibility Initiative
Providing Alternatives for Multimedia Content
14.4.1 Readability
14.4.2 Using Voice Synthesis and Recognition with Voice XML
Accessibility in Microsoft Windows 2000
14.5.1 Tools for Visually-Impaired People
14.5.2 Tools for Hearing-Impaired People
14.5.3 Tools for Users Who Have Difficulty Using the Keyboard
14.5.4 Microsoft Narrator
14.5.5 Microsoft On-Screen Keyboard
14.5.6 Accessibility Features in Microsoft Internet Explorer 5.0
Other Accessibility Tools
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14.1 Introduction
• Persons with disabilities make up a significant
portion of the population, and legal ramifications
exist for Web sites that discriminate by not
providing adequate and universal access to the
site’s resources
• In this chapter, we explore:
– The Web Accessibility Initiative and its requirements
– Various laws regarding businesses and their availability to
people with disabilities
– How some companies have developed their systems,
products and services to meet the needs of this demographic
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14.2 Web Accessibility
• In 1999, a lawsuit was filed by the National
Federation for the Blind (NFB) against AOL for
not supplying access to its services to people with
visual disabilities, a mandate of the Americans
with Disabilities Act of 1990
• WeMedia.com is dedicated to providing disabled
individuals with the same opportunities as the
general population
– Provides online educational opportunities for people with
disabilities
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14.2 Web Accessibility
Ac t
Purp o se
Americans with Disabilities Act
The ADA prohibits discrimination on the basis of disability in employment, state and
local government, public accommodations, commercial facilities, transportation, and
telecommunications.
Telecommunications Act of 1996
The Telecommunications Act of 1996 contains two amendments to Section 255 and
Section 251(a)(2) of the Communications Act of 1934. These amendments require
that communication devices, such as cell phones, telephones and pagers, be
accessible to individuals with disabilities.
Individuals with Disabilities
Educational materials in the school setting must be made accessible to children with
Education Act of 1997
disabilities.
Acts designed to protect access to the Internet for people with disabilities.
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14.2 Web Accessibility
We Media home page. (Courtesy of We Media Inc.)
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14.2 Web Accessibility
• The Internet has also enabled disabled individuals
to work in a vast array of new fields
– Prior to its advent, 25 percent of the 15 million Americans
with disabilities found employment as a result of the
Americans with Disabilities Act (ADA)
– Technologies such as voice activation, visual enhancers and
auditory aids afford disabled individuals with more work
opportunities
– Information provided through technology will have to be
equally accessible to individuals with disabilities
– Sites heavily laden with graphic images might have to
simplify their appearance
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14.3 Web Accessibility Initiative
• On April 7, 1997, the World Wide Web
Consortium (W3C) launched the Web Accessibility
Initiative (WAI )
– An attempt to make the Web more accessible
• Accessibility
– Refers to the level of usability of an application or Web site
for people with disabilities
– The vast majority of Web sites are considered inaccessible to
people with visual, learning or mobility impairments
– A high level of accessibility is difficult to achieve
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14.3 Web Accessibility Initiative
• The Web Content Accessibility Guidelines 1.0 are
divided into a three-tier structure of checkpoints
according to their priority
– Priority-one checkpoints are those that must be met to
ensure accessibility
– Priority-two checkpoints, though not essential, are highly
recommended
– Priority-three checkpoints improve accessibility slightly
– The WAI also presents a supplemental list of quick tips—this
list contains checkpoints aimed at solving priority one
problems
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14.4 Providing Alternatives for
Multimedia Content
• WAI requirement
– Ensure that every image, movie and sound used on a Web
page is accompanied by a description called an ALT tag that
clearly defines its purpose
• Intended to provide a short description of an HTML object
which may not load properly on all user agents
• Specialized user agents
– An application that interprets Web-page source code and
translates it into formatted text and images
– Screen readers are programs that allow users to hear what is
being displayed on their screen
– Braille displays are devices that receive data from screenreading software and output the data as braille
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14.4 Providing Alternatives for
Multimedia Content
– Web pages with large amounts of multimedia content are
difficult for user agents to interpret, unless designed properly
• Images, movies and other non-HTML objects cannot be read
by screen readers
– Provide multimedia-based information in a variety of ways
– User-agent technology is unable to make image maps
accessible to blind people or others who cannot use a mouse
• Include a link at the top of each Web page that
provides easy access to the page’s content so users
can use the link to bypass inaccessible elements
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14.4.1 Readability
• Readability
– When creating a Web page intended for the general public, it
is important to consider the reading level at which it is
written
• Use of shorter words
• Users from other countries may have difficulty understanding
slang and other nontraditional language
• Web Content Accessibility Guidelines 1.0
– Suggests that a paragraph’s first sentence convey its subject
• Gunning Fog Index
– A formula that produces a readability grade when applied to
a text sample
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14.4.2 Using Voice Synthesis and
Recognition with Voice XML
• VoiceXML
– An XML application that uses speech synthesis to enable the
computer to speak to the user
– Has tremendous implications for visually impaired people
and for people who cannot read
• Reads Web pages to the user, also includes speech recognition
technology—which enables computers to understand words
spoken into the microphone
• ViaVoice
• VoiceXML processed by a VoiceXML interpreter or browser
• Platform independent
• When a VoiceXML document is loaded, a voice server sends a
message to the VoiceXML browser and begins a conversation
between the user and the computer
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14.5 Accessibility in Microsoft
Windows 2000
• Since Microsoft Windows 95, Microsoft has
included accessibility features in its operating
systems and many of its applications
• Accessibility Wizard
– Guides a user through the Windows 2000 accessibility
features and configures the computer according to the
chosen specifications
• Microsoft Magnifier
– A program that displays an enlarged section of the
screen in a separate window
• Disable personalized menus
– A feature that hides rarely used programs from the
Start menu
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14.5.1 Tools for Visually Impaired
People
• Users can resize scroll bars and window borders to
increase their visibility
• Users can resize icons
– Users with poor vision—as well as users who have trouble
reading—benefit from large icons
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14.5.1 Tools for Visually Impaired People
Text Size dialog
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14.5.1 Tools for Visually Impaired
People
Display Settings dialog
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14.5.1 Tools for Visually Impaired
People
Accessibility Wizard initialization options
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14.5.1 Tools for Visually Impaired
People
Scroll Bar and Window Border Size dialog
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14.5.1 Tools for Visually Impaired
People
Setting window element sizes
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14.5.1 Tools for Visually Impaired
People
• Settings allow the user to change Windows’ color
scheme and to resize various screen elements
• Wizard offers the user the choice of using larger
cursors, black cursors and cursors that invert the
colors of objects underneath them
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14.5.1 Tools for Visually Impaired
People
Display Color Settings options
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14.5.1 Tools for Visually Impaired
People
Accessibility Wizard mouse cursor adjustment tool
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14.5.2 Tools for Hearing-Impaired People
• SoundSentry
– A tool that creates visual signals when system events occur
• ShowSounds dialog
– Enables you to add captions to spoken text and other sounds
produced by today’s multimedia-rich software
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14.5.2 Tools for Hearing-Impaired
People
SoundSentry dialog
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14.5.2 Tools for Hearing-Impaired
People
Show Sounds dialog
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14.5.3 Tools for Users Who Have
Difficulty Using the Keyboard
• StickyKeys
– A program that helps users who have difficulty pressing
multiple keys at the same time by allowing the user to press
key combinations in sequence
• BounceKeys
– Forces the computer to ignore repeated keystrokes
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14.5.3 Tools for Users Who Have
Difficulty Using the Keyboard
StickyKeys dialog
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14.5.3 Tools for Users Who Have
Difficulty Using the Keyboard
BounceKeys dialog
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14.5.3 Tools for Users Who Have
Difficulty Using the Keyboard
• ToggleKeys
– Alerts the user that they have pressed one of the lock keys
(i.e., Caps Lock, Num Lock and Scroll Lock), by sounding an
audible beep
• Extra Keyboard Help dialog
– Used to activate a tool that displays information, such as
keyboard shortcuts and tool tips, when they are available
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14.5.3 Tools for Users Who Have
Difficulty Using the Keyboard
ToggleKeys dialog
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14.5.3 Tools for Users Who Have
Difficulty Using the Keyboard
Extra Keyboard Help dialog
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14.5.3 Tools for Users Who Have
Difficulty Using the Keyboard
• MouseKeys
– A tool that uses the keyboard to emulate mouse movements
– The arrow keys direct the mouse, while the 5 key sends a
single click
– To double click, the user must press the + key, and to
simulate holding down the mouse button, the user must press
the Ins (Insert) key
– To release the mouse button, the user must press the Del
(Delete) key
• Mouse Button Settings window
– Tool allows the user to create a virtual lefthanded mouse, by
swapping the button functions
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14.5.3 Tools for Users Who Have
Difficulty Using the Keyboard
Fig. 14.16 MouseKeys window
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14.5.3 Tools for Users Who Have
Difficulty Using the Keyboard
Mouse Button Settings window
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14.5.3 Tools for Users Who Have
Difficulty Using the Keyboard
• Mouse speed is adjusted using the MouseSpeed
– Dragging the scroll bar changes the speed
• Set Automatic Timeouts window
– Specifies a timeout period for the tools
• A timeout either enables or disables a certain action after the
computer has idled for a specified amount of time
• Save Settings to File dialog determines
whether the accessibility settings should be used
as the default settings, which are loaded when the
computer is rebooted or after a timeout
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14.5.3 Tools for Users Who Have
Difficulty Using the Keyboard
Mouse Speed dialog
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14.5.3 Tools for Users Who Have
Difficulty Using the Keyboard
Set Automatic Timeouts
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14.5.4 Microsoft Narrator
• Microsoft Narrator
– A text-to-speech program for visually impaired people
– Reads text, describes the current desktop environment and
alerts the user when certain Windows events occur
– A screen reader that works with Internet Explorer, Wordpad,
Notepad and most programs in the Control Panel
• The Voice... button enables the user to change the
pitch, volume and speed of the narrator voice
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14.5.4 Microsoft Narrator
Narrator Window
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14.5.4 Microsoft Narrator
Narrator reading Notepad text
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14.5.5 Microsoft On-Screen
Keyboard
• On-Screen Keyboard
• Clicker 4 by Inclusive Technology
– Developed as an aid for people who cannot effectively use a
keyboard
– Keys can have letters, numbers, entire words or even
pictures on them
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14.5.5 Microsoft On-Screen
Keyboard
Microsoft On-Screen Keyboard
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14.5.6 Accessibility Features in
Microsoft Internet Explorer 5.0
• The accessibility options in Microsoft Internet
Explorer 5.0 augment the user’s Web browsing
– Users are able to ignore Web colors, Web fonts and font-size
tags
– Users can specify a style sheet that formats every Web site
the user visits, according to that user’s personal preferences
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14.5.6 Accessibility Features in
Microsoft Internet Explorer 5.0
Microsoft Internet Explorer 5.0’s Accessibility options
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14.5.6 Accessibility Features in
Microsoft Internet Explorer 5.0
• Always expand ALT text for images
– By default, Internet Explorer 5.0 hides some of the <ALT> text, if
it exceeds the size of the image it describes
– Forces all of the text to be shown
• Move system caret with focus/selection changes
– Intended to make screen reading more effective
– Some screen readers use the system caret (the blinking vertical bar
associated with editing text) to decide what is read and if this
option is not activated, screen readers may not read Web pages
correctly
• Allows the user to select text size
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14.5.6 Accessibility Features in
Microsoft Internet Explorer 5.0
Advanced accessibility settings in Microsoft Internet Explorer 5.0
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14.5.6 Accessibility Features in
Microsoft Internet Explorer 5.0
Accessing the Text Size menu in Microsoft Internet Explorer 5.0
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14.6 Other Accessibility Tools
• Software exists to help those with different types
of disabilities
• Braille keyboard
– Similar to a standard keyboard except that in addition to
letters on every key, it has the equivalent braille symbol
– Most often, braille keyboards are combined with a speech
synthesizer or a braille display, so users are able to interact
with the computers and verify that their typing is correct
– The development of speech synthesizers is also enabling
other technologies, such as VoiceXML and AuralCSS to
improve
• Allow visually impaired people and those who cannot read to
access Web sites
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14.6 Other Accessibility Tools
• Markup languages
– Languages such as HTML and XML, designed to layout and link
text files
• Hearing-impaired Web users benefit from Synchronized
Multimedia Integration Language (SMIL )
– Designed to add extra tracks—layers of content found within a
single audio or video file
• Products are also being designed to help severely
handicapped persons
– EagleEyes, developed by researchers at Boston College, is a
system that recognizes a user’s eye movements and translates them
to move the cursor
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14.6 Other Accessibility Tools
• CitXCorp
– Developing technology that translates information over the
Web through the telephone
• Information on regulations governing the design
of Web sites to accommodate people with
disabilities can be found at www.access-board.gov
• Adobe Acrobat and Adobe’s PDF
– Will be manufactured to comply with Microsoft’s
application programming interface (API), allowing
businesses to reach a disabled audience
• JetForm Corp. server-based XML software
– Allows users to download a format modified to best meet
their needs
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14.6 JAWS Feature
• JAWS (Job Access With Sound) is a screen reader
– Created by Henter-Joyce, a division of Freedom Scientific
and a company that tries to help visually impaired people use
technology
• The JAWS demo is fully functional and includes
an extensive help menu that is highly customized
– User can select which voice to utilize, the rate at which text
is spoken and create keyboard shortcuts
– JAWS also includes special key commands for popular
programs, such as Microsoft Internet Explorer and Microsoft
Word
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