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[techs] Alt Text Tests 192 and 195

From: Chris Ridpath <chris.ridpath@utoronto.ca>
Date: Fri, 21 Jan 2005 10:00:32 -0500
Message-ID: <04a901c4ffc9$f422d790$e29a968e@WILDDOG>
To: "WAI WCAG List" <w3c-wai-gl@w3.org>

On our last techniques phone conference we discussed tests for Alt text. It
was felt by the group that two of the tests still required more discussion
so I'm posting this message. The two tests under discussion are:

192 Alt text for all INPUT elements with a TYPE attribute value of "image"
does not use the words "submit" or "button" (English).
http://www.w3.org/WAI/GL/WCAG20/tests/test192.html

195 - Alt text for all IMG elements used as source anchors does not begin
with "link to" or "go to" (English).
http://www.w3.org/WAI/GL/WCAG20/tests/test195.html

The purpose of these tests is to increase the quality of Alt text by
restricting common text strings. These tests also relate to link text which
hasn't received much discussion yet. I think that both of these tests should
be a level 2 or level 3 requirement.

These tests check for text strings in the English language. We will have to
include text strings for other languages as well.

Test 192 deals with form submit buttons and restricts the use of the words
"submit" and "button". It's explicit in the HTML code that the INPUT element
is a form submit button so it's redundant to put that text on the button.
Instead the author should put the purpose of the button such as "find",
"search" or "purchase".

Another common word that could be excluded is the word "go". Example at our
ATRC web site http://atrc.utoronto.ca There's a form near the top of the
page that is used for searching the site that uses the word "go" to submit
the form. It would be more accessible if the button was labeled "search".

After viewing a form and filling in its fields the user knows what the
submit button will do so it's not critical that the submit button has a good
label. However if there is many forms on the page and they all use the same
form submit button label, such as "go", it can be difficult to figure out
which "go" relates to which form. We could loosen our test to make it
applicable only if there are more than X number of forms that use the same
submit button label. I favour applying the test to all submit buttons
because of consistency. It makes the rule simpler and easier to apply.

Questions:
- Is this test useful?
- Are there other words that should be excluded?
- Should it be applied only if there are X number of forms on the page?

Test 195 deals with images used as links and restricts the use of "link to"
and "go to" at the beginning of the Alt text. It's already explicit in the
HTML code that this is a link and screen readers can tell the user that.
Example code:
<a href="home.html"><img src="house.png" alt="link to home page"/></a>
In the example, a screen reader would read "link" twice like "link link to
home page". This is not such a big problem when there is only one link like
this but when there are many links like this it can be disorienting. This
sort of code is common in navigation bars.

Note that we related tests to 195:
15 - Alt text for all IMG elements used as source anchors identifies the
destination of the link.
http://www.w3.org/WAI/GL/WCAG20/tests/test15.html
7 - Alt text for all IMG elements used as source anchors is not empty when
there is no other text in the anchor.
http://www.w3.org/WAI/GL/WCAG20/tests/test7.html
175 - Alt text for all IMG elements used as source anchors is different from
the link text.
http://www.w3.org/WAI/GL/WCAG20/tests/test175.html

Questions:
- Is this test useful?
- Are there other words that should be excluded?
- Should it be applied only if there are X number of links like this?

The current state of the test suite is described at:
http://www.w3.org/WAI/GL/WCAG20/tests/checkstatus.html
(Please refresh your browser to get the most current view.)

Comments appreciated.

Cheers,
Chris
Received on Friday, 21 January 2005 15:02:30 GMT

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