Making Your Web Site Accessible to the Blind
by Curtis Chong
Director of Technology
National Federation of the Blind
Access to the Internet-specifically, access to the World Wide Web-by persons with disabilities has been a subject of considerable interest in the media. The techniques for ensuring accessibility to a Web site by persons with disabilities are documented by the Web Access Initiative of the World Wide Web Consortium on its Web site at http://www.w3.org/wai/.
The purpose of this article is to provide guidance to Web site developers who want to ensure that their Web pages are accessible to and usable by the blind. Inasmuch as we have expertise in the strategies used by the blind to obtain and process information without sight, we will confine this discussion solely to considerations of nonvisual access.
The recommendations in this article are made based upon the known capabilities of the technology used by the blind to surf the Web. However, this technology is in a continual state of flux. Problems identified in the context of today's nonvisual access technology will probably be solved in a future release. For example, there was a time when a Web page using frames was inaccessible to the blind. With enhancements in Web-browsing and screen access software, that problem is largely behind us. It is important, therefore, for Web site developers to plan on keeping in touch with nonvisual access technology developers and the National Federation of the Blind to ensure that they maintain a keen awareness of the continually-improving capability of nonvisual access technology.
How Do Blind People Surf the Web?
A blind person surfing the Web will most likely use very much the same computer as someone who is sighted. While a small number can surf the Web using a Macintosh computer equipped with the appropriate screen access software, the majority of blind computer users will be found with a personal computer running Windows. The basic personal computer is supplemented by technology called screen access software, which translates information on the screen into synthesized speech or Braille. The program used to surf the Web will most likely be Microsoft Internet Explorer. Other browsing techniques are possible, ranging from the use of Lynx (a text-only browser written originally to run under Unix) to browsing packages such as IBM's Home Page Reader, which generate their own speech.
When entering a Web page, the blind person will probably check out the hypertext links that are on the page. This is usually accomplished by jumping from link to link with the Tab key; the screen access software automatically reads the highlighted text as the focus moves from link to link. If the highlighted text is something like "How to Contact Us" or "Visit Your Shopping Cart," the blind user will be able to make some sense out of the link. If, however, the highlighted text is "Click Here," or "Here," it will be difficult if not impossible for the blind user to interpret the meaning of the link without using a different navigation strategy. With the more recent screen access software/browser combinations, it is possible for the blind Web surfer to explore the page one line at a time, thus alleviating this problem. However, being forced to examine every detail of a Web page just to learn the meaning of a hypertext link is a time-consuming process which, ideally, should be avoided.
However the page is navigated, the important point to keep in mind here is that the screen access software is looking for ascii text, which it can convert to speech or braille. Such text can be obtained either directly from the screen or by examining the html (hypertext markup language) which comprises the "source code" for the page. For example, if the blind user encounters a graphical object (e.g., a picture or a company logo) on a Web page that has no text, the information that is spoken depends on how the graphic is labeled. If the graphic is labeled with an "alt" tag, the screen access software will speak the text string associated with the tag. If not, then the screen access software might try to ascertain the name of the file which constitutes the graphic. If the name is something meaningful such as "company-logo.gif," the blind user may be able to infer that the graphic is a picture of a company logo. if, on the other hand, the name of the gif file is something like "image01.gif," then there is no way that the blind user can even begin to guess at the nature of the image.
Once the desired hypertext link has been located, the blind person presses the Enter key (clicks on the link) to go where the link points. If there is a form to fill out on the page, the blind person will usually tab to the appropriate input field and type the information in the usual way. Other controls such as checkboxes, combo boxes, radio buttons, and the like can all be used if the screen access software can detect them.
Recommendations for the Web Site Developer
Screen access software needs to have enough information so as to render any given Web site to the blind Web surfer in a meaningful way. The suggestions shown below will help in this regard. We are not trying here to tell the Web developer what to do to make a given Web page accessible. Rather, we approach the problem by telling the Web developer what the blind user needs in order to use a Web site. Once the developer understands what is needed, the specific strategy for how to achieve the goal is, rightfully, up to the developer.
PROVIDE SCREEN ACCESS SOFTWARE WITH THE ASCII TEXT IT NEEDS TO PRODUCE SPEECH OR BRAILLE. Generally speaking, this means using ASCII text wherever possible'in hypertext links, in document content, on push buttons, in menus, and in the labeling of graphical objects. Screen access software can only work with ASCII text'not bit-mapped images of text.
MAKE IT POSSIBLE FOR BLIND WEB SURFERS WHO EXPLORE YOUR WEB PAGE BY TABBING FROM LINK TO LINK TO DETERMINE THE MEANING AND PURPOSE OF ALL HYPERTEXT LINKS ON THE PAGE. This means providing meaningful text labels for hypertext links. Labels such as "click here" or "more" do little to impart meaning.
ENABLE SCREEN ACCESS SOFTWARE TO PROVIDE INFORMATION TO THE BLIND WEB SURFER ABOUT PURELY GRAPHICAL OBJECTS ON THE PAGE. This could mean labeling each graphic with an HTML "ALT" tag or naming the file representing the graphic so that the graphic can be identified simply by hearing its name.
ENSURE THAT THE USE OF TABLES AND MULTI-COLUMN TEXT ON YOUR WEB SITE DOES NOT PRECLUDE THE ABILITY OF SCREEN ACCESS SOFTWARE TO RENDER YOUR PAGES IN AN INTELLIGIBLE AND USEFUL MANNER. While the more advanced screen access software of today can navigate the tables used on today's Web pages, some cannot. Moreover, even the most sophisticated screen access software will have trouble with tables that contain many columns, as is the case with bus or train schedules.
MAKE IT POSSIBLE FOR THE BLIND WEB SURFER TO FILL OUT WEB-BASED FORMS IN AN EFFICIENT MANNER. Forms contain controls such as edit fields, check boxes, combo boxes, list boxes, and several types of buttons(e.g., Submit buttons, Radio buttons, etc.). Generally speaking, screen access software has no problem identifying these controls. However, there are certain ways of laying out a form which can prove to be troublesome for blind Web surfers. In particular, forms where headings for specific input fields are not adjacent to the fields will continue to be a problem until Web site developers use the "LABEL" tag on all such fields and screen access software provides information from that tag to the blind user. To illustrate the point, consider a simple form like this:
First Name: Last Name: Middle Initial:
___________ _________ _______________
If the Web page is being examined line by line, the blind user will hear something like this: "first name, last name, middle initial, edit, edit, edit."
In a simplified form such as this, it is possible to memorize the order of the fields and enter the correct information. But in a more complex layout, where there might be ten or more fields on a line, memorization will not work. Hence, there is a definite need to identify input fields in such a way that the blind Web surfer will have no doubt as to the information to be entered.
PROVIDE A MEANS FOR BLIND WEB SURFERS TO AVOID REDUNDANT LINKS ON A WEB PAGE. It is fairly commonplace for Web sites to place navigation links on each and every page of the site'links such as "return to home page," "how to contact us," and the "like." It is not uncommon for there to be upwards of twenty or more such links on a page. While a person who can see the page can ignore these links, a blind Web surfer must read through them with screen access software to reach the information on the page that is actually wanted. This is a time-consuming process which hampers the efficiency of the blind Web surfer and often serves to make the Web surfing process a frustrating experience. One possible solution is to provide a version of the site which does not contain navigation links on each page. Alternatively, consider incorporating a "skip navigation" link at the beginning of the page; this link, if selected, would move the focus to the information on the page that the author of the page intends for the user to read. It can be made invisible to a sighted user but detectable by screen access software. Examples of the use of this type of link can be found at IBM's Accessibility Center (http://www.ibm.com/sns) or on the news pages of CNN (http://www.headlinenews.cnn.com/).
PROVIDE A MEANS FOR BLIND WEB SURFERS TO AVOID SPLASH SCREENS OR OTHER DISPLAYS THAT ARE UPDATED ON A TIMED BASIS. Screen access software requires that a display remain static so that the blind Web surfer has enough time to examine the information on a page. There is nothing more frustrating for a blind Web surfer than to have spent minutes moving through a Web page to find an article only to have that page updated by a splash screen. When the splash screen appears, the focus of the screen access software is pulled back to the top of the page, forcing the user to move through the page again to find the article to be read. If your design requires dynamic screen updating, provide the blind Web surfer with a way to use your site with static Web pages that are only updated at the user's discretion.
Vendors of Screen Access Software for the Blind
Here are Web sites for three screen access software developers/vendors. Web site developers who want to ensure that their work will not shut out the blind should check with one or more of these companies to better understand the interplay between commercial Web browsers and screen access software.
Freedom Scientific: http://www.freedomscientific.com/. Freedom Scientific manufactures and msells JAWS for Windows, a complete screen access program for the Windows operating system.
GW Micro: http://www.gwmicro.com/. GW Micro makes Window-Eyes, a complete screen access program for the Windows operating system.
Visioncue: http://www.visioncue.com/. The Alva Access Group's screen access software for Windows is called outSPOKEN.
Accessibility-Related Web Sites
The following list of Web sites is not meant to be all inclusive. However, referring to these sites will help to provide you with more detailed information to help you make your site more accessible'not only for the blind, but also for people with other disabilities.
The World Wide Web Consortium's Quick Tips to Make Accessible Web Sites: http://www.w3.org/wai/references/quicktips. This is a quick reference card which provides a quick look at what needs to be done to make your site accessible.
The Bobby Accessibility Checker: http://www.cast.org/bobby. The Bobby software can be used to generate a report on a Web site's overall accessibility. It is a good start to determining if your site has a few or a lot of accessibility issues to contend with.
Designing More Usable Web Sites: http://trace.wisc.edu/world/web/. This is a publication of the Trace Center from the University of Wisconsin in Madison, Wisconsin.
IBM's Accessibility Guidelines: http://www-03.ibm.com/able/guidelines/web/accessweb.html. These are software and Web accessibility guidelines in force within the IBM Corporation.