Web accessibility WCAG 2.0 short Guideliness


What’s good in WCAG 2.0 :

The latest version of web content accessibility guidelines 2.0 (WCAG 2.0) are divided into 4 principles (POUR) –

  • Perceivable,
  • Operable,
  • Understandable
  • Robust

Each principle is divided into guidelines with priority levels A, AA, AAA.

The WCAG 1.0 has 14 guidelines but are not divided into blocks.

This has been taken care in WCAG 2.0 in the form of principles. The explanations of the checkpoints are given in separate hyperlinks.

Important Issues in WCAG 2.0

1.Table:

Tables are one of the most widely used attributes in HTML and they do create problems in the accessibility of the web page. Even though tables are not used for the visual layout in the recent era ,they are used to present the important data in a tabular form. WCAG 2.0 provides no information about tables and the ways in which they can be used whereas WCAG 1.0 guideline 5 entirely speaks about HTML tables.

Example:

The following example consists of two parts: the CSS code, which specifies a margin on all sides of the table, and padding for the table cells; and the HTML code for the table, which does not contain spacer images and is not nested inside another table.

Code:

table { margin: .5em; border-collapse: collapse; }
              td, th { padding: .4em; border: 1px solid #000; }

            ...

              <table summary="Titles, authors and publication dates of books in Web development category">
                <caption>Books in the category 'Web development'</caption>
                <thead>
                  <tr>
                    <th>Title</th>
                    <th>Author</th>
                    <th>Date</th>
                  </tr>
                </thead>
                <tbody>
                  <tr>
                    <td>How to Think Straight About Web Standards</td>
                    <td>Andrew Stanovich</td>
                    <td>1 April 2007</td>
                  </tr>
                </tbody>
              </table>
Refer: http://www.w3.org/TR/WCAG-TECHS/C18.html

2.Users of older browsers and turn-off features:

WCAG 2.0 includes the turn-off feature for the ones who use older browsers that do not support images, java script and so many new features.

3.Auto refreshing and auto redirecting:

The features such as auto refreshing, auto redirecting and causing pop-ups create problems for visually impaired users who can be both low vision and screen reader users. These features are explained clearly in check points 7.4 & 7.5 in WCAG 1.0 but were not defined in WCAG 2.0.

4.Usage of deprecated features of HTML:

WCAG 2.0 does not contain any information about deprecated features of HTML, that cannot be used as per WCAG 1.0.

5.Usage of frames:

The usage of frames is clearly explained in checkpoints 12.1 & 12.2 of WCAG 1.0 but were left unexplained in the latest version of WCAG.

6.Usage of style sheets:

Nowadays, most of the web designers are using CSS for visual lay out of the web pages. WCAG 2.0 do not contain any relevant information about the usage of style sheets.

7. Usage of HTML doc type:

There are no guidelines about doc type declaration in WCAG 2.0 where as WCAG 1.0 has it explained. The latest version did not focus much on the alidation of HTML and its perfect usage.

8. Usage of links in meaningful sequence:

WCAG 2.0 guidelines 1.3.2 defines that the links should be presented in meaningful sequence so that the user can use the track to find the required information easily. In the checkpoint 1.3.2 it is given that any audio or video should not play continuously for more than 3 seconds, if it plays the user has to be given an option to pause or stop, or at least have a mechanism to reduce the volume without changing the over all system volume.

9. Input errors:

This is one of the issue, where WCAG 1.0 didn’t focus  much, but it does have a vital role in web pages. This was nicely explained in the guideline 3.3 of latest version.

Some more issues raised by WCAG 2.0 are:

1. Foreground and background colors selected by the user.
2. Width should not be more than 80 characters or glyphs (40 if CJK).
3. Text is not justified (aligned to both the left and the right margins).
4. Line spacing (leading) is at least space-and-a-half within paragraphs, and paragraph spacing is at least 1.5 times larger than the line spacing.
5. Text can be resized without assistive technology up to 200 percent in a way that does not require the user to scroll horizontally to read a line of text on a full-screen window.

Test Tools:

WAVE – http://wave.webaim.org/toolbar
Firefox Accessibility extension
Add-ons of Mozilla Firefox https://addons.mozilla.org/en-US/firefox/search?q=accessibility&cat=all

Screen Readers
NVDA – http://www.nvda-project.org
JAWS for Windows – http://www.freedomscientific.com
Screen Magnifiers
ZoomText Xtra – http://www.aisquared.com
Dolphin Supernova – http://www.yourdolphin.com
Alternate Input devices –
Track ball and switch – http://www.ablenetinc.com
Dragon Naturally Speaking
http://www.nuance.com
Talks – a screen reader for mobile S60 phones
http://www.nuance.com/talks/

Some Useful Links:

http://www.bentoweb.org/XHTML1_TestSuite3

http://www.webcredible.co.uk/user-friendly-resources/web-accessibility/wcag-guidelines-20.shtml

http://www.it-analysis.com/business/compliance/content.php?cid=11303



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