2001 prentice hall, inc. all rights reserved. chapter 14, accessibility outline 14.1introduction...

2001 Prentice Hall, Inc. All rights reserved.

Chapter 14, Accessibility

Outline14.1 Introduction14.2 Web Accessibility14.3 Web Accessibility Initiative 14.4 Providing Alternatives for Multimedia Content

14.4.1 Readability14.4.2 Using Voice Synthesis and Recognition with Voice XML

14.5 Accessibility in Microsoft Windows 200014.5.1 Tools for Visually-Impaired People14.5.2 Tools for Hearing-Impaired People14.5.3 Tools for Users Who Have Difficulty Using the Keyboard14.5.4 Microsoft Narrator14.5.5 Microsoft On-Screen Keyboard14.5.6 Accessibility Features in Microsoft Internet Explorer 5.0

14.6 Other Accessibility Tools


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


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



Act Purpose

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 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.



We Media home page. (Courtesy of We Media Inc.)



• 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


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


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


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 screen-reading software and output the data as braille


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


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


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


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


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



Text Size dialog



Display Settings dialog



Accessibility Wizard initialization options



Scroll Bar and Window Border Size dialog



Setting window element sizes



• 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



Display Color Settings options



Accessibility Wizard mouse cursor adjustment tool


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



SoundSentry dialog



Show Sounds dialog


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



StickyKeys dialog



BounceKeys dialog



• 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



ToggleKeys dialog



Extra Keyboard Help dialog



• 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



Fig. 14.16 MouseKeys window



Mouse Button Settings window



• 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



Mouse Speed dialog



Set Automatic Timeouts


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



Narrator Window



Narrator reading Notepad text


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


14.5.5 Microsoft On-Screen Keyboard

Microsoft On-Screen Keyboard


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



Microsoft Internet Explorer 5.0’s Accessibility options



• 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



Advanced accessibility settings in Microsoft Internet Explorer 5.0



Accessing the Text Size menu in Microsoft Internet Explorer 5.0



• 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



• 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



• 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


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

2001 prentice hall, inc. all rights reserved. chapter 14, accessibility outline 14.1introduction...

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