UNIVERSAL USABILITY IN PRACTICE

In 1994 and 1995, among people age 6 and over, 8.8 million had difficulty seeing, and 10.1 million had difficulty hearing.  The number unable to see was 1.6 million, and 1.0 million were unable to hear [McNeil95].  In fact, a significant number of user requirements for people with disabilities apply to almost any user, given the right circumstance or task context.  Whether users do not hear because they are talking to others on the phones, paying attention to their tasks, working in a noisy environment, or happen to be deaf are less important than the fact that users in these contexts need alternate sources of information.

Providing accessibility means removing barriers that prevent people with disabilities from participating in substantial life activities, including the use of services, products, and information.  We see and use a multitude of access-related technologies in everyday life, many of which we may not recognize as disability related when we encounter them.  The bell that chimes when an elevator is about to arrive, for example, was designed with blind people in mind.  Accessibility is by definition a category of usability: software that is not accessible to a particular user is not usable by that person.  As with any usability measure, accessibility is necessarily defined relative to user task requirements and needs.  Graphical user interfaces are not very accessible to blind users, but relatively accessible to deaf users.  Furthermore, people with listening impairments have difficulties hearing sounds generated by computers, such as error signals.  Nowadays, multimedia plays very important roles especially in the web services.  However, little effort has been applied to providing complementary information to the deaf and hearing-impaired users.

Many people who are born deaf learn American Sign Language (ASL) as their first language in the United States.  Most of them learn English as their second language.  Since most of the web pages offer English versions in the United States, people cannot avoid English if they want to use the web.  English and ASL are so different on the structure and the grammars.  Similar to the people whose native language is not English, their writings have errors such as missing "be" verbs or the plural, wrong verb tense spelling, improper proposition or determiners, subject/verb not in agreement, etc.

Sign languages of deaf and hearing-impaired people are fully formed natural languages linked to cultural values and social behaviors of deaf communities.  Sign languages differ from spoken languages of the majority, hearing communities in obvious ways: their modality of production (gestural vs. oral) and perception (visual vs. aural).  By sign language interface, we mean ways of representing deaf sign languages for computer storage and display in order to permit input, retrieval, and manipulation by people [Frishberg93].  Computer technology offers the opportunity to create tools that enable literacy and learning in ways accessible to signing users.

Additionally, there are some stronger reasons to develop universally usable websites for deaf and hearing-impaired users.  It's the law.  Many countries have laws that mandate accessibility at some level.  In the United States, there are three laws that cover this area:

• The Americans with Disabilities Act states that all businesses with 15 or more employees must make reasonable accommodation for employees or potential employees with disabilities.  This act entitles individuals to sue their employers or prospective employers if the software they use isn't accessible.  This act was interpreted to also require commercial Web sites to be accessible. [Gunderson94]
• Section 508 of the Rehabilitation Act has a similar effect on the government and any organization receiving federal funding.  New legislation is in the works to strengthen enforcement of these requirements.  The Federal Government is the single largest purchaser of computer software.
• Section 255 of the Telecommunications Act requires hardware and software manufacturers to ensure that products are usable by individuals with disabilities, or compatible with existing accessibility aids commonly used by individuals with disabilities to achieve access, if readily achievable.  This may apply to any hardware or software that transfers information over the Internet, a network, or phone lines. 

Many strategies for deaf and hearing-impaired users provide advantages for those with perfect hearing.  Substituting audio alerts with visual alerts enables use in noisy environments or quiet ones.  Providing transcriptions of spoken language or song lyrics, makes them searchable, easily scanned, and translatable by machine translation programs.

Lengthy checklists can be widely found on the Internet [W3WAI][IBM01], but here are three basic guidelines of the design for deaf and hearing-impaired users [Sun01].

• Provide visual information that is redundant with audible information.
• Allow users to configure frequency and volume of audible cues.
• Do not design interactions to depend upon the assumption that a user will hear audio information.

In the past, sounds generated by computers have been fairly simple and used primarily to indicate different types of errors or keyboard buffer overflows.  For simple sounds, ways have been developed to present the sounds visually.  The importance of sound in computer applications is rapidly changing.  The introduction of multimedia technologies is making speech and complex sounds an important part of interacting with computer systems [Gunderson94].  For deaf and hearing-impaired people to have access to multimedia applications, ways need to be developed to support the presentation of complex sounds and closed captioning for speech.

The following illustrates how the computer needs of people with disabilities are being met [Microsoft01].

• Hardware or operating system adaptations.  Options and features that refine mouse and keyboard control, add sound, or increase visual contrast should be built into the operating systems and hardware.  For example, Microsoft Windows 98 and Windows 2000 include an Accessibility Wizard to help people adapt various operating system features to their needs.  These same options can be accessed from the Windows operating system Control Panel.
• Features in software.  Features such as customizable color and the ability to zoom in on text and screen images can help make software readily accessible.  Many of these features are built into many software programs and may be accessed from the Format or View menus. However, most people with disabilities need to use mainstream software programs to take advantage of the latest features and to facilitate working or sharing information with their friends and coworkers.
• Accessibility aids.  Work with a computer's operating system to accommodate specific impairments, such as a limited range of motion or blindness.  Products include larger keyboards, eye-gaze-operated keyboards, voice input utilities, on-screen keyboards, and products that can convert text to speech or to a dynamic Braille display.
• Specialized software.  Some software is created specifically to meet the needs of people with disabilities. For example, some word processing programs are being designed to integrate voice and text to help individuals with limited abilities read or type.

• Gather requirements to understand deaf and hearing-impaired people's needs, abilities and preferences before designing.
• Consult end-users, teachers, and interpreters.
• Think about the similarities and differences between the spoken language and the sign language.
• Apply second language acquisition theory to design the system.

HTML provides a text equivalent for non-text elements.  This includes: images, graphical representations of text, image map regions, animations, applets and programmatic objects, ASCII art, frames, scripts, images used as list bullets, spacers, graphical buttons, sounds, stand-alone audio files, audio tracks of video, and video.  Two contents are considered as equivalent when both fulfill essentially the same function or purpose upon presentation to the user.  For example, the text "The Happy Birthday Song" might convey the same information as an audio clip of the melody when presented to users.  Equivalent information focuses on fulfilling the same function.  Providing equivalent information for inaccessible content is one of the primary ways authors can make their documents accessible to people with disabilities.  Text equivalents must be written so that they convey all essential content.

A text transcript is a text equivalent of audio information that includes spoken words and non-spoken sounds such as sound effects.  A caption is transcript for the audio track of a video presentation that is synchronized with the video and audio tracks.  Captions are generally rendered visually by being superimposed over the video, which benefits people who are deaf and hard-of-hearing, and anyone who cannot hear the audio (e.g., when in a crowded room).  A collated text transcript combines (collates) captions with text descriptions of video information (descriptions of the actions, body language, graphics, and scene changes of the video track).  These text equivalents make presentations accessible to people who are deaf-blind and to people who cannot play movies, animations, etc.  It also makes the information available to search engines.  One example of a non-text equivalent is an auditory description of the key visual elements of a presentation.  The description is either a prerecorded human voice or a synthesized voice (recorded or generated on the fly).  The auditory description is synchronized with the audio track of the presentation, usually during natural pauses in the audio track.  Auditory descriptions include information about actions, body language, graphics, and scene changes. 

Equivalent information may be provided in many ways:  adding a text value for the "alt" attribute in HTML and SMIL; writing part of "object" element content in HTML; designating the "longdesc" attribute via a linked document in HTML.  Here is an example of a resource requiring a plug-in.  For backward compatibility with Netscape browsers, the proprietary "EMBED" element should also be provided within the "OBJECT" element as follows:
 

Example.   <OBJECT classid="clsid:A12BCD3F-GH4I-56JK-xyz"     codebase="http://example.com/content.cab" width=100 height=80>      <PARAM name="Movie" value="moviename.swf">      <EMBED src="moviename.swf" width=100 height=80        pluginspage="http://example.com/shockwave/download/">      </EMBED>     <NOEMBED>        <IMG alt="Still from Movie"         src="moviename.gif" width=100 height=80>      </NOEMBED>    </OBJECT>

3.2 Text Equivalents for Real-time Audio [W3Core00]:

For any time-based multimedia presentation (e.g., a movie or animation), the provider should synchronize equivalent alternatives (e.g., captions or auditory descriptions of the visual track) with the presentation.  Besides, it is also important to ensure that dynamic content is accessible or provide an alternative presentation or page.  Auditory presentations must be accompanied by text transcripts, textual equivalents of auditory events.  When these transcripts are presented synchronously with a video presentation they are called captions and are used by people who cannot hear the audio track of the video material.

Some media formats (e.g., QuickTime 3.0 and SMIL) allow captions and video descriptions to be added to the multimedia clip.  SAMI allows captions to be added.  The following example demonstrates that captions should include speech, as well as other sounds in the environment that help viewers understand what is going on.  Until the format you are using supports alternative tracks, two versions of the movie could be made available, one with captions and descriptive video, and one without.  Some technologies, such as SMIL and SAMI, allow separate audio/visual files to be combined with text files via a synchronization file to create captioned audio and movies.  Some technologies also allow the user to choose from multiple sets of captions to match their reading skills.  Equivalents for sounds can be provided in the form of a text phrase on the page that links to a text transcript or description of the sound file.  The link to the transcript should appear in a highly visible location such as at the top of the page.  However, if a script is automatically loading a sound, it should also be able to automatically load a visual indication that the sound is currently being played and provide a description or transcript of the sound.
 

Example. Captions for a scene from "E.T." The phone rings three times, then is answered.   [phone rings]   [ring]   [ring]   Hello?"

• The World Federation of the Deaf (WFD) is an international organization composed of 120 national associations of the deaf which, in collaboration with the United Nations, serves all countries in the enhancement of the social, economic and cultural lives of deaf and hard of hearing people.
• The National Association of the Deaf (NAD, USA) is organized and operated mainly to promote the welfare of deaf and hard of hearing people in education, economic, security, social equality, and just rights and privileges as citizens.
• The Self Help for Hard of Hearing People (SHHH, USA) is to enhance the quality of life for people who are hard of hearing.
• The Canadian Hearing Society (CHS, Canada) provides services that enhance the independence of deaf, deafened and hard of hearing people, and that encourage prevention of hearing loss.
• The British Deaf Association (BDA, UK) is a national charity representing about 70,000 Deaf people in the United Kingdom.  It is the leading edge of the Deaf movement in Europe.
• The purpose of the Chinese National Association for the Deaf, R.O.C. (CNAD, Taiwan) is to improve the quality of living for deaf and hearing-impaired people through actions that impact deaf culture, arts, skills, sports and publishing in accordance with the current government policy.

• British Deaf Association offers text-only pages to support the older versions of some web browsers.  This is particularly helpful for the people who cannot afford newer versions.  This site is Bobby [Bobby01] approved.
• DEAF.com offers variance online services through the textual interfaces for services without any audio effect, such as chat rooms, newsgroups and media publishing.
• Microsoft Corporation offers step-by-step guides for hearing impairments to customizing Microsoft products to meet the user accessibilities.

There are some sign language tools in the market now, but none of them works well enough on the Internet services.  Signwriting was introduced to offer more realistic communication tool for the deaf and hearing-impaired people in the daily life.  The telephony devices may be good tools for Internet communication, too.  It should be possible to provide the same kinds of interaction on the web.  These two topics are listed as the next part of this report.

Audio clips and streams on the web can be accompanied by either textual caption or video sign language translation, like some airline safety video presentations have accompanying sign language translations.  Web developers still have many questions.  What are efficient ways to use computer graphic techniques to provide (artificial human "talking" sign language) on the web?  How to choose between the general textual outputs and the signwriting figures?

A client side approach can be embedded a web browser as was done in the Virtual Signing, Animation, Capture, Storage, and Transmission (ViSiCAST) Project [Elliott00].  They developed a framework supporting the translation of natural text into the gesture-oriented notation.  ViSiCAST seeks to support improved access by deaf citizens to information and services an their chosen medium of sign languages.

6.2 Telecommunications Device for the Deaf (TDD) on the Web:

A typical TDD device 'rings' via flashing light or the more recent vibrating wristband that resembles a watch.  The TDD consists of a keyboard,
which holds somewhere from 20 to 30 character keys, a display screen, and a modem.  The letters that the TDD user types into the machine are turned into electrical signals that can travel over regular telephone lines.  When the signals reach their destination (in this case another TDD) they are converted back into letters that appear on a display screen, are printed out on paper or both.  Some of the newer TDDs are even equipped with answering machines.

Without a means to translate audible information on the Internet, the deaf and hearing-impaired people were excluded from some services that most take for granted.  The TDD affords the deaf and hearing-impaired people the same luxury that hearing persons have.  There should be a similar application or device for web browsing and searching.  How can TDD technology serve as a web browser?  How to embed TDD inputs and outputs through existing computers?  All these remain as open questions.