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This tends to disenfranchise some users, however. When we put up web pages to provide information to our clientele, we need to remember their limitations, and make our information accessible. Deaf readers need text support for sound clips, as well as visual clues to any audio stimuli, including beeps and bells. Blind readers need to be able to access the information content through text presented in a linear manner, so that it can be rendered as sound by their specialized equipment. Readers at the end of a telephone line need access to the information content even when they turn off display of inline images, and readers with older computers need pages that work with a text browser, such as Lynx.
The presentation will demonstrate HTML coding techniques to enhance accessibility without totally forsaking attractiveness. The potential audience will be web authors who can understand HTML tagging without lengthy explanations.
Screen readers do a pretty amazing job of translating the characters on a screen, reading from left to right and top to bottom, into phonemes which are spoken by the hardware. Most screen readers take total control of the hardware, however, and override the possibility of playing embedded sound files through the sound card. A specialized web page reader, {pwWebSpeak}, overcomes this limitation. Pages designed to be taken in at a glance, using colors and type sizes to draw the eye to particular parts, take on a whole new "look" when read aloud serially.
Many hearing readers have non-speaking computers (no sound cards). Both deaf readers and these impoverished souls (including most users of Library computers) are helped by web authors who include a text alternative, or at least a description, for each audio clip.
Webmasters who count access by browser type cite low percentages of Lynx users as justification for using the more resource intensive HTML features. This smacks of the self-fulfilling prophecy; who would visit www.sears.com a second time with Lynx or with images turned off? In a recent exchange on the web-consultants discussion list, Gregory J. Rosmaita, under the pseudonym Oedipus wrecked, suggests that the number of non-graphic browser users is understated:
even a cursory glance at the lynx-dev mailing list's hypertext archives would reveal that, currently, there are Japanese, Chinese, Egyptian, Turkish, Brazilian, American, Canadian, German, Swedish, Ukranian, Russian, and a host of other programmers working on national charsets, libraries, and patches for lynx... if lynx's user base was as small as is claimed on this list, it would have breathed its last with the release of 2.4.2 (Gill, The Web: Design, ADA and Lynx)
Many Web authors do not know the differences among the HTML standards, and may not realize how badly the pages they write with WYSIWYG editors may present themselves in diverse browsers. Gerald Oskoboiny does us all a great service with his "Kinder, Gentler Validator" at {http://ugweb.cs.ualberta.ca/~gerald/validate/} where he offers HTML grammar checking and Weblint style analysis. If you submit a page without a <!DOCTYPE> declaration it will be parsed at HTML 2.0 level and the information that Gerald makes available will teach you much about the various flavors of HTML.
Oskoboiny also provides a way to see approximately how your pages would appear in Lynx without launching a Lynx browser. http://cgi.w3.org/cgi-bin/html2txt? is the address; this is actually a script that requires a URL as an argument, but try the address given to get further instructions from Gerald directly.
Text expressed not in ASCII characters but as part of an image, often in a banner or letterhead image, must be expressed in alt="the words in the image" to avoid losing content without the image.
Larger images should be presented in thumbnail versions, with a link to their larger selves to be loaded on demand. The link text would include the thumbnail image itself and an indication of its approximate size in kilobytes, as in this example: <a href="asiamin.gif"><img src="asiamic.gif" width=44 height=26 alt="[Map: Asia Minor]"> 47K</a> The full-size image will be loaded as a separate page if the link is selected by the user. Since it stands alone, no provision for including its width and height is needed.
An image editor, such a LviewPro or Photoshop, can easily create smaller versions of .gif or .jpg images for use as thumbnails. It is also possible to use the same file for both, with the width and height attributes used to tell the browser to reduce the image size on the fly, but this means asking the user to do with each load work that can be done once only. This is a blatant violation of Ranganathan's fourth law of library science, "Save the time of the Reader."
Images that are purely decorative, contributing to the look of the graphic page but useless to the non-graphic browser user, can be hidden from the latter's sight or hearing by using the alt= parameter to make the alternative text a null or empty string: <img src="wavyline.gif" width=480 height=5 alt=""> Note that there is absolutely nothing between the quotes.
My preference is to use link text in association with images that suggest the target, if appropriate. I welcome the blue border and the bright blue underlined text convention that gives the user belt-and-suspenders assurance that this is indeed a link.
Linking to a site that automatically starts playing a tune can be quite disconcerting on a browser that cannot play the tune; an error message is likely to pop up in the user's face. One such is the satiric {http://www.highersource.org/} site (not to be confused with the .com site), which plays the theme from M*A*S*H ("Suicide is Painless") as background.
Not all browsers can handle forms. If you are really concerned about giving the reader a means to provide information to you or your organization, provide alternatives. Many sites give users a choice among:
While it is beyond the scope of this paper, when possible moving pictures may be made accessible by adding captions in text or in ASL and by providing a descriptive soundtrack for blind users. If such options are available, they should probably be provided in side-by-side alternative links, rather than included in the only copy of the movie provided. (Vanderheiden)
I also added a <br> tag at the end of almost every URL that was expressed as such in the text. This really helps clarify to the hearer that the end of the link has been reached, especially when the speech synthesizer tries to interpret and pronounce the "words" in the URL; for example, the synthesizer reads the "ca" in ugweb.cs.ualberta.ca as "California."
| Table type | Results in Lynx | Screen reader results |
|---|---|---|
preformatted text in columns and rows | spacing of the original text is preserved in fixed spacing typeface | line-by-line reading does violence to the logic of the text arrangement |
| <table>standard table construction</table> | all table-related tags are ignored, text is presented in a blob, line by line ignoring line ends | same as above |
| standard table construction with <br> tags at end of each cell | table-related tags are ignored, but <br> tags cause new line starts; significance of headings is lost | if screen reader is reading Lynx screen, new line indicates new topic, but logic of columns may not be obvious |
Michael Reagan KK6WO Circulation Unit Coordinator mreagan@csun.edu University Library (818) 677-4391 fax (818)677-4136 California State University home (818) 449-0996 fax 449-0952 Northridge CA 91330-8327 pager (818) 828-1226 packet KK6WO@W6VIO.#SOCA.CA.USA.NA --... ...-- -.. . de gustibus non est disputandum -.- -.- -.... .-- ---The roster of the CSU, Northridge Faculty Executive Committee is an example of the use of table logic with <br> tags to make it work in Lynx. Its URL is {http://www.csun.edu/~fs20469/execom.html} and it has an extra <br> tag in the right-hand cells to create vertical white space between entries when displayed in Lynx.
If you do feel a need to use frames logic, create the page without it as well, and include a link at the top of the frames page to let your readers get to the non-frames version. Do this for every page on which you use frames. If you are within the range of normally lazy humanity, you will stop putting yourself through the agony of writing the frames version.
If your WYSIWYG HTML tool insists on writing with frames, throw it out.
Microsoft ActiveX has most of the same disadvantages as Java plus a reputation for creating security problems that has many users refusing to allow it.
My graphic editor is the freeware LviewPro. When I open an image file the upper border displays the file name and its three dimensions, width in pixels, height in pixels, and number of colors in the palette used. It is amazing how much difference can be made in the size of the image file by reducing the number of colors used. A scanned image of a postcard printed on a wood-grain background was 62,151 bytes in .jpg format. As seen in an experiment with LviewPro at {http://library.csun.edu/reagan/images.html} the size was reduced to 30,569 bytes by limiting the number of colors, and further reduced to 18,345 bytes by saving it in .gif format. Choosing a reduced file size, if the image quality is still adequate, "Saves the time of the Reader."
Smaller image sizes help keep the total page size within reason. Pages larger than 50K to 75K total should be scrutinized carefully. Many readers will hit the stop button rather than wait to see large pages. (Gill, Issues)
Many users are annoyed by blinking text and animated .gif images, but a few could be injured by them. Some epileptic seizures are triggered by pulsing light. Blinking text is pulsing light. Need I complete the syllogism?
Screen readers used to translate text into speech or Braille are usually stymied by blinking text, making it impossible for the user to read the rest of the screen.
Just don't.
Screen readers of the future, optimized for HTML, are likely to do a better job of expressing <strong>, <em>, <cite>, or <var> than <b> or <i>. (DO-IT)
Yet, HTML is a Markup Language. It is designed to separate content from specific presentation of information. It expects the designer to indicate sentences, paragraphs, etc. in a simple way to format clear text. Yet many page designers, in an effort to create a "magazine on the screen," have resorted to clever techniques to extend the range of HTML. They endeavor to force the browser to "display" that information in a specific way--a method which may exactly match the format which the designer might pick if he/she had complete control. (Murphy)This effort is doomed to failure, because the balance of power in the Web is shifted away from the page producer. The look and feel of a web page is determined by three elements:
Dardailler, Daniel, Paciello, Michael G. 1997. "W3C
Disabilities Developments." [{http://www.w3.org/WAI/References/}]
Includes links to most of the helpful sites dealing with accessible HTML.
Design Visualization Laboratory at the University of Illinois at Chicago. 1997. "NCSA Mosaic Access Page.". [{http://bucky.aa.uic.edu/}]
DO-IT Disabilities, Opportunities, Internetworking & Technology. 1997. "DO-IT HTML Guidelines." [{http://www.washington.edu/doit/}]
Flavell, A. J. 1997. "Imagemaps - Text-friendly? Cache-friendly?" [http://ppewww.ph.gla.ac.uk/%7Eflavell/alt/imgmap.html]
Fontaine, Paul. 1997. "Writing Accessible HTML Documents." [{http://www.itpolicy.gsa.gov/cita/wwwcode.htm}]
Addresses many of the practicalities in this paper with clear rationales, strategies, and examples of both inaccessible code and accessible alternatives.
Gill, Kathy E. "Issues of Web Design:
Multiple Browser Compatibility."
[{http://www.enetdigest.com/design/design.html}]
An
introduction with selected links.
Gill, Kathy E. 1997. "The Web: Design, ADA and Lynx."
[{http://www.enetdigest.com/design/text_ada.html}]
An exchange of messages on the web-consultants distribution list.
Gunderson, Jon. 1997. "World Wide Web Accessibility to
People with Disabilities A Usability Perspective."
[http://www.staff.uiuc.edu/~jongund/access-overview.html]
Speaks of features that should be added to browsers, HTML editors, and
information formats (e.g. movies) to enhance accessibility.
MacCandlish, Stanton. 1997. "Designing HTML Tables to Work with HTML 2.0 Browsers." [{http://www.eff.org/~mech/Scritti/html_table_design.html}]
Demonstrates "tricks" to make tables look acceptable in a non-tables browser.
Murphy, Arthur R. 1997. "Design
Considerations: Readers with Visual Impairments."
http://www.lcc.gatech.edu/gallery/dzine/access/]
Urges use of Lynx as a measure of accessibility.
Paciello, Mike. 1997. "Making the
Web Accessible for the Blind and Visually Impaired."
[{http://www.yuri.org/webable/mp-blnax.html}]
Describes access considerations for "print-impaired" users.
Yuri Rubinsky Insight Foundation. 1997. "WEBable."
[{http://www.yuri.org/webable/}]
Another good source for web sites on access.
Starling Access Services. 1997. "Accessible Web Page Design." [{http://www.igs.net/~starling/acc/}]
Vanderheiden, Gregg C. 1997.
"Design of HTML pages to increase
their accessibility to users with disabilities: strategies for today and
tomorrow, version 6.0."
[{http://www.yuri.org/webable/htmlglds.html}]
Mixes practical suggestions for today with wishes and hopes for the
future.