Chapter 14 - Accessibility. The following will be discussed in this chapter: Web accessibility, web accessibility initiative, providing alternatives for multimedia content, accessibility in Microsoft Windows 2000, other accessibility tools.
Trang 114.5.1 Tools for VisuallyImpaired People 14.5.2 Tools for HearingImpaired People 14.5.3 Tools for Users Who Have Difficulty Using the Keyboard 14.5.4 Microsoft Narrator
14.5.5 Microsoft OnScreen Keyboard 14.5.6 Accessibility Features in Microsoft Internet Explorer 5.0 14.6 Other Accessibility Tools
Trang 2• 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
Trang 3• 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
Trang 4Americans 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
Education Act of 1997 Educational materials in the school setting must be made accessible to children with disabilities. Acts designed to protect access to the Internet for people with disabilities.
Trang 5We Media home page. (Courtesy of We Media Inc.)
Trang 6• 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
Trang 7– 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
Trang 8• The Web Content Accessibility Guidelines 1.0 are divided into a threetier structure of checkpoints according to their priority
Trang 9Multimedia 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 Webpage 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 screen
reading software and output the data as braille
Trang 10• 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
Trang 11• 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
Trang 12• Reads Web pages to the user, also includes speech recognition
technology—which enables computers to understand words spoken into the microphone
Trang 14People
• 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
Trang 15Text Size dialog
Trang 16People
Display Settings dialog
Trang 17People
Accessibility Wizard initialization options
Trang 18People
Scroll Bar and Window Border Size dialog
Trang 19People
Setting window element sizes
Trang 20People
• 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
Trang 21People
Display Color Settings options
Trang 22People
Accessibility Wizard mouse cursor adjustment tool
Trang 24People
SoundSentry dialog
Trang 25People
Show Sounds dialog
Trang 26Difficulty 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
– Forces the computer to ignore repeated keystrokes
Trang 27Difficulty Using the Keyboard
StickyKeys dialog
Trang 28Difficulty Using the Keyboard
BounceKeys dialog
Trang 30Difficulty Using the Keyboard
ToggleKeys dialog
Trang 31Difficulty Using the Keyboard
Extra Keyboard Help dialog
Trang 32– Tool allows the user to create a virtual lefthanded mouse, by swapping the button functions
Trang 33Difficulty Using the Keyboard
Fig. 14.16 MouseKeys window
Trang 34Difficulty Using the Keyboard
Mouse Button Settings window
Trang 35as the default settings, which are loaded when the
computer is rebooted or after a timeout
Trang 36Difficulty Using the Keyboard
Mouse Speed dialog
Trang 37Difficulty Using the Keyboard
Set Automatic Timeouts
Trang 38• Microsoft Narrator
– A texttospeech 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
Trang 39Narrator Window
Trang 40Narrator reading Notepad text
Trang 41– Keys can have letters, numbers, entire words or even
pictures on them
Trang 42Keyboard
Microsoft On-Screen Keyboard
Trang 4314.5.6 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 fontsize tags
– Users can specify a style sheet that formats every Web site
the user visits, according to that user’s personal preferences
Trang 4414.5.6 Accessibility Features in Microsoft Internet Explorer 5.0
Microsoft Internet Explorer 5.0’s Accessibility options
Trang 4514.5.6 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
– 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
Trang 4614.5.6 Accessibility Features in Microsoft Internet Explorer 5.0
Advanced accessibility settings in Microsoft Internet Explorer 5.0
Trang 4714.5.6 Accessibility Features in Microsoft Internet Explorer 5.0
Accessing the Text Size menu in Microsoft Internet Explorer 5.0
Trang 48• Allow visually impaired people and those who cannot read to access Web sites
Trang 49• Markup languages
– Languages such as HTML and XML, designed to layout and link text files
• Hearingimpaired Web users benefit from Synchronized Multimedia Integration Language (SMIL )
Trang 50• 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.accessboard 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. serverbased XML software
– Allows users to download a format modified to best meet their needs
Trang 51• JAWS (Job Access With Sound) is a screen reader
– Created by HenterJoyce, 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