tools to increase accessibility of the webweb4.uwindsor.ca/units/oucc2004/forms.nsf... · oucc 2004...

Tools to Increase Accessibilityof the Web

Clare SoDepartment of Computer Science

University of Western OntarioLondon, Ontario. N6A 5B7

[email protected]

OUCC 2004 - May 16-18, 2004

OUCC 2004 - Web Accessibility 1

Aim of this Talk

• What is accessible Web?

• Who are obligated to provide accessible Web?

• Many FREE tools available!


Outline

• Clare

– Goals of accessibility

• Mark

– Obligations

• Stephen

– Accessibility mechanisms


In a Perfect World


In Reality


What is Web Accessibility?

• Viewable and useful for target population

• ”Able to get something out of it!”

Why Making the Web Accessible?

• More than showing good ethics!

• Legal obligations

• Increase clients

– Pages can be read using different technologies (example: phone)


What is a Web site?


What is a Web site?

• Not just an aesthically pleasing page!

• Consist of more than text and pictures

– Math

– Music (score, sound clip)

– Chemistry formulae

• Accomodate a wide variety of

– Users (students, professors, public)

– Knowledge


How to Make the Web Inaccessible?

• Imaged text

– Enlarging fonts?

– Searching for keywords?

• No “alt” text in <img>

– Text browsers

– Exception: Put email address in an image without “alt” text → spam list

• Non-standard HTML

– Displaying pages using different browsers?


Free Tools - Markup Validation Service

• Offer by World Wide Web Consortium

• Point out HTML markup that does not conform to the standard

– Example: missing ”alt” attribute in images

• http://validator.w3.org/

Free Tools - HTML Tidy

• Clean up improper markup

– Example: missing closing tag

• Give suggestions to improve accessibility

• Version for many OSs available

• http://tidy.sourceforge.net/


Free Tools - WAI Checklists

• Offer by Web Accessibility Initiative (WAI),World Wide Web Consortium

• Three different level of conformance

– Priority 1 - Basic requirement

– Priority 2 - Remove significant barriers

– Priority 3 - Bells and whistle

• Some criteria are to be checked manually

• http://www.w3.org/WAI/


Free Tools - Some of WAI Quick Tips

• Images & animations: Use the alt attribute to describe the function of eachvisual.

• Multimedia. Provide captioning and transcripts of audio, and descriptionsof video.

• Hypertext links. Use text that makes sense when read out of context. Forexample, avoid ”click here.”

• Page organization. Use headings, lists, and consistent structure. UseCSS for layout and style where possible.

• Scripts, applets, & plug-ins. Provide alternative content in case activefeatures are inaccessible or unsupported.

• Check your work. Validate. Use tools, checklist, and guidelines athttp://www.w3.org/TR/WCAG

(c) W3C (MIT, INRIA, Keio) 2001/01


Demo - UWO Library Homepage


Demo - Validating UWO Library Homepage


Demo - Tidying UWO Library Homepage


What Do These Error Messages Mean?

• Markup Validation Service gives 67 errors such as

– Line 5, column 42: there is no attribute ”TYPE”<link rel="icon" href="favicon.ico" type="image/x-icon">

– Line 250, column 8: there is no attribute ”ID”<div id="headerdiv" z-index=2>

– Line 272, column 66: required attribute ”ALT” not specified...T COORDS="17,77,139,115" HREF="/crcatalogues.shtml">

• HTML Tidy gives 90 warnings such as

– line 77 column 1 - Warning: <script> inserting ”type” attribute

– line 245 column 1 - Warning: <div> proprietary attribute ”z-index”

– line 260 column 540 - Warning: <area> lacks ”alt” attribute

– line 320 column 1 - Warning: <table> lacks ”summary” attribute


What Do These Error Messages Mean?

• ”alt” text missing

• Authoring tools that do not conform to Web standard

• Web page may not be rendered meaningfully in a text-based browser

tools to increase accessibility of the webweb4.uwindsor.ca/units/oucc2004/forms.nsf... · oucc 2004...

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