Jutta Treviranus,University of Toronto
Chris Serflek, University of Toronto
Contents
The World Wide Web
Browsers
Web Accessibility
Document Structure and Content
Browsers and Alternative Access Systems
Research and Development at the Adaptive Technology ResourceCentre
Virtual Reality Modeling Language
Conclusions
References
The World Wide Web
The World Wide Web (Web or WWW) is quickly becoming the most popularinformation architecture on the Internet. Many features which make the WWWappealing as a method of serving information are also the features which createbarriers for users of alternative access systems.
The Web is a seemingly limitless system of information servers worldwide, whichare tied together by hypertext links. Through hypertext links, relatedinformation or documents can be retrieved without regard to their location.Documents served on the Web are constructed using a standard markup language,Hypertext Markup Language (HTML), so that they are "display systemindependent". Thus the documents can be viewed on various platforms (DOS,Windows, OS/2, MAC, Unix etc.), using various browsers or system dependentsoftware programs. The documents can contain or provide links to: colorgraphics, digital sound, music, digital videos, interactive maps or otherrepresentation formats. The Web contains an endless variety of informationincluding up-to-the-minute weather maps or traffic reports, on-linepublications, language lessons with sample pronunciations, movie memorabilia,simulations, and resource information on almost every topic.
In order to use the Web an individual must have a computer with sufficientmemory, an Internet connection which provides Web access, a fairly fast modem(9600 or 14.4 baud) or other link and a Web browser. Browsers are applicationprograms which run on the user's computer and receive and display the Web HTMLdocuments. Browsers provide the user interface for the Web.
Browsers
While the documents served over the Web or standardized, the browsers andtherefore the user interface are not. A large number of Web browsers are basedon NSCA Mosaic, the original graphical Web browser available free on theInternet. The leading alternative is Netscape Navigator. Internet accessproviders frequently supply proprietary browsers with their service. IBMprovides a Mosaic based browser with OS/2 WARP and Microsoft is planning tofollow suit with the next release of Windows. The leading non-graphical Webbrowser is Lynx which is available for Mac, DOS and Unix platforms.
Web Accessibility
Previous Internet architectures and communication packages, which providedtext one-line-at-a-time or in clearly structured hierarchical menus, werereadily adapted to work with most alternative access systems. The flexibilityand richness of the Web also presents the greatest access challenges. Webdocuments contain some information in exclusively audio, visual and graphicform. Frequently, critical components of a document have graphics only labels.Hypertext links can occur anywhere in a document and are identified by purelygraphical characteristics such as color, bolding or graphic images with coloredoutlines. With the exception of Lynx and other text based browsers, most Webbrowsers have graphical user interfaces. Web documents are created with theassumption that the browser will display graphics, video and audio.
Document Structure and Content
A number of these problems can be resolved by carefully designing the HTMLdocuments. Paul Fontaine (Clearinghouse on Computer Accommodation, emailThis email address is being protected from spambots. You need JavaScript enabled to view it.) providesguidelines on writing more accessible HTML documents. These guidelines include:
- providing associated text with every graphic image,
- providing an alternate method of selecting options when image maps areused,
- including detailed descriptive "comments" with all JPEG images,
- providing text transcriptions or descriptions for all audio clips, and
- providing an alternative to the use of forms.
These guidelines can be followed within the present constraints of HTML andwithout compromising the aesthetics or functionality of the documents.
The structure of a document, including the layout and visual formatting,provides important information needed to browse, search, navigate and review adocument. This structural information is inaccessible to many people with printimpairments (International Committee for Accessible Document Design, 1994). Inan effort to provide this structural information independent of therepresentation system used, the International Committee for Accessible DocumentDesign (ICADD) has developed a set of 22 " document organizing" elements (tags) which identify the structural elements of documents andfacilitate the translation of those documents into Braille. In addition theyhave specified a mechanism for incorporating these tags or attributes into thenext version of HTML (HTML 3.0 due to be released in 1995). Efforts are underwayto expand the base set of 22 tags to include tags for representing mathematical expressions, graphics, tables and other formats. Until the release of HTML 3.0 anumber of organizations are offering the service of translating standard HTMLdocuments into ICADD22 documents which are then Braille ready.
Browsers and Alternative Access Systems
Many users with print impairments avoid a large number of access issuesencountered when browsing the Web by using a text-based browser such as Lynx.Lynx continues to be supported as it requires less computational power and canbe used by individuals with older or less expensive computers. As thecomputational standard shifts dramatically Lynx will lose support. Many Webinformation servers ignore Lynx users, structuring documents such that importantinformation is not available to text based browsers.
In order to navigate through the World Wide Web, retrieve information and beable to interpret or read the information, three things must be properly adaptedto the user. These are: 1) the HTML document, 2) the browser and 3) thealternative access system. The HTML document must contain the information in anaccessible or redundant form and must contain tags which provide structuralinformation. The browser should allow a range of display and user interfaceoptions. The browser can also incorporate some standard access features andhooks for less common alternative access systems. The alternative access systemshould take advantage of the information in the document (including the documenttags) and the hooks in the browser. These three things must also be compatiblewith each other. Any effective access solutions will require modifications toall three components.
Research and Development at the Adaptive Technology Resource Centre
Three projects are presently underway at theUniversity of Toronto ,Adaptive Technology Resource Centre. Thefirst is a project which systematically evaluates the compatibility ofalternative access systems with the most popular Web browsers. Ease and abilityto control all browser functions and necessary customizations are assessed anddocumented through this project. This project is ongoing and the information isregularly updated. There is insufficient space to publish the results of theproject in this paper. Any information published would be largely outdated uponpublication. The information will be available through the Web sitehttp://idrc.ocad.ca or bycontacting the authors.
The browsers assessed include NSCA Mosaic for MAC, Windows and Unix; Netscapefor MAC and Windows; the IBM browser provided with the WARP operating system;and Lynx for DOS, MAC and Unix. This list is steadily growing as new browsersappear on the market. Alternative access systems evaluated includealternative keyboard systems (e.g.,Ke:nx, Wivik, Doors products), voice recognition systems (e.g., Dragon Classic, Dragon for Windows, VoiceType forOS/2, and the Kurzweil system), screen magnifiers (e.g., Inlarge, Zoomtext Plus, Magic Deluxe, Lyon),screen readers (e.g., Screen Reader forDos and OS/2, WinVision, Business Vision, Vert, Outspoken for MAC and Windows)and Braille displays (e.g.,Navigator, Power Braille).
The evaluations are performed by experienced users of the access technologiesand students with technical expertise in the Web and Web browsers. Tasksevaluated include:
- moving between and choosing hypertext links
- accessing the menu
- accessing buttons or "Hot Spots"
- completing forms
- viewing and manipulating Gopher and FTP documents
- down loading Text as Binary, Audio, JPEG, GIF and MPEG files
- manually entering URLs
- accessing help systems, and
- entering search strings.
The second project explores the creation of more accessible Web documents within and beyond the constraints of HTML. Throughthis project a model Web site is being created which will demonstrate and allowthe evaluation of document structures, while serving information from Canadianresources for people with disabilities. This project is being carried out inconjunction with SoftQuad and ARCH.
A project still in the planning stages will create an accessible browser. Theapplication program to be created will act as both a browser and as a utility orviewer to be used with other Mosaic browsers. This browser will containinterface options and the appropriate hooks to make it accessible to users ofalternative access systems.
Virtual Reality Modeling Language
While working on the accessibility of the present form of the World WideWeb, we must also remain cognizant and provide input to new developments. Onesuch development is the creation and specification of VRML (Virtual RealityModeling Language)(Bell, Parisi, Pesce, 1994). VRML is a proposed protocol forthe World Wide Web. It is a language for describing multi-participantinteractive simulations. These simulations are to be hyperlinked through theWorld Wide Web. This is intended to allow users to participate in distributedvirtual reality environments.
Early implementations of VRML have very limited interactive behaviors. It isproposed however that all aspects of virtual world display, interaction andnetworking be specified using VRML. We must insure that information in VRML canbe displayed in alternative or multimodal formats and that the interface can becontrolled through a number of alternative input devices and systems.Compatibility with alternative access technology must be monitored as this newstandard is being specified.
Conclusions
The Internet and the World Wide Web are becoming important informationresources in education, business and every day life. Unfortunately, recentadvances in display technology have caused set-backs in access for individualswith sensory or print impairments. Development, research and education arerequired in the accessibility of present Internet architectures as well asproposed architectures.
References
International Committee for Accessible Document Design. (1994). A positionpaper regarding a FIPS for electronic document interchange. unpublishedmanuscript. Bitnet address This email address is being protected from spambots. You need JavaScript enabled to view it..
Bell, G., Parisi, A., Pesce, M., 1994. The Virtual Reality Modeling Language,Version 1.0 Specification (DRAFT). URL:http://www.web3d.org/x3d/specifications/vrml/VRML1.0/index.html