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Re: alt-text authoring guidelines

From: Liam Quinn <liam@htmlhelp.com>
Date: Thu, 09 Apr 1998 19:26:31 -0400
Message-Id: <3.0.5.32.19980409192631.0097e320@undergrad.math.uwaterloo.ca>
To: w3c-wai-gl@w3.org
At 05:23 PM 09/04/98 -0500, Wendy A Chisholm wrote:
>We have tried to synthesize all of the comments and discussion about how to
>author alt-text for use in the Page Authoring guidelines.  Please read
>http://trace.ie.wisc.edu/kaboodle/html/tests/alt.htm

LQ::

For "Images and Image maps" (section 2.1--the first one), the first
paragraph is great, but the examples in that section don't agree with the
advice.  ALT="XYZ Logo" does not represent the function of the image; it
represents a description of the image.  ALT text representative of the
function of the image might be "XYZ" or "Welcome to XYZ", depending on the
context.

Section 2.1.1 recommends using ALT for APPLET and INPUT.  I don't think ALT
should be used with APPLET since alternate content can be given more
effectively as the content of the APPLET element, allowing full markup
whereas ALT text is limited to plain text.  With INPUT, it should be
clarified that the ALT attribute is only necessary for <INPUT TYPE=image>.

Section 2.2 (which should actually be 2.3) reads as follows:

| To avoid confusion, if an alternative list of links follows the image
map, authors should indicate with | the "alt" attribute of the MAP element
that there is an alternate list and its location.

LQ::  There is no ALT attribute on the MAP element.  Substituting "IMG" for
"MAP", the advice seems to suggest ALT text of the form "See text links
below".  Is this really helpful to those not loading images?  If there are
text links later in the document, the user will get to them.  Saying "See
text links below" seems like another reminder that the Web is made for
people who can see graphics.  (Of course "below" is also a poor word choice
on my part since "below" makes no sense aurally; describing the location in
a device-independent way is too difficult to bother with, in my opinion.)

If text links are provided in addition to an IMG-based image map, I'd
suggest using ALT="" to remove the redundant object for those not loading
images.  (And now people will say that they want to know that an image is
there, and I will say that they're thinking of the Web as a visual medium
and hurting accessibility... <g>)

Section 2.3.2 (on MAPs including A elements) suggests the use of the TITLE
attribute of A.  The example basically just repeats the content of the A
element in the TITLE attribute, which seems rather pointless.  If the
content of the A element were an abbreviated version and the TITLE
attribute gave a full title for the linked resource, use of TITLE would
make sense, but I don't think that TITLE should be used when it just
repeats information that is more easily available elsewhere.  We have to
avoid unnecessary redundancies so that user agents don't start assuming
that the TITLE attribute is not worth presenting.

Section 2.4 suggests the use of the TITLE attribute on all A elements that
contain an IMG.  Good, functional ALT text should accomplish the same task,
as in this modified example from 2.4:

<A href="home.html"><IMG src="logo.gif" alt="XYZ company home page"
title="XYZ Logo"></A>

Note that this provides the necessary information to the many user agents
that lack support for the TITLE attribute.  Even if TITLE were universally
supported, I think the preceding use of ALT and TITLE is more sensible.  An
alternative would be as follows:

<A href="home.html" title="XYZ company home page"><IMG src="logo.gif"
alt="XYZ" title="XYZ Logo"></A>

Here I've added the TITLE attribute to A since I've used an abbreviated ALT
text.

In the "Guidelines for writing alt-text", it's suggested that ALT text
should end with "proper punctuation, such as a colon or period".  I'm not
sure if it's the intention or not, but this seems to suggest that all ALT
attribute values should end with some form of punctuation.  First off, ALT
text may be part of a sentence, in which case punctuation would most often
be inappropriate.  Secondly, I commonly use <H1><IMG src="logo.gif"
alt="XYZ Company"></H1>, without trailing punctuation since I want it to be
presented as <H1>XYZ Company</H1> to those not loading images.  If
punctuation should be used in my ALT text here, then it should also be
recommended for the end of each heading, which doesn't seem right.

For the TITLE attribute, I think the best and most natural way to use it is
to provide a title for the IMG, A, or whatever element.  Each image could
have a title if it were on its own ("XYZ Logo", "My Wedding Photo", and so
on).  A elements that link to HTML documents would typically use the linked
document's TITLE element as the value of the A element's TITLE attribute,
though if the A element's content provides an adequate title this would
just be redundant.

For decorative graphics, I think we need to distinguish between important
decorative graphics (such as some photographs) and fluff.  Many decorative
images, such as a small mailbox icon next to someone's e-mail address,
would be best marked up with ALT="" since they are of no use to those not
loading images.  Decorative photographs (which in many respects are
content) could use descriptive ALT text, though I'd suggest surrounding the
ALT text with delimiters such as "[" and "]" to ensure that the ALT text is
not misunderstood in a given context.  An example of such a problem is the
"Photo of a bull in the water canoeing" howler from Alan Flavell's article
on ALT text [1].

For graphical bullets, I don't see any harm in using style sheets to
provide a graphical bullet where the graphical bullet provides no meaning
(as is the case with Example 2).  In this case, the non-graphical browser
would simply render the list item marker as it normally would, which should
not be a problem.  The danger is if the graphical bullet is depended upon
to provide a meaning; suitable use of the CLASS attribute could indicate
the meaning and style sheets (aural, visual, etc.) could help express it,
though the author should not depend on any presentation getting the meaning
across.

[1] http://ppewww.ph.gla.ac.uk/%7Eflavell/alt/alt-text.html

--
Liam Quinn
Web Design Group            Enhanced Designs, Web Site Development
http://www.htmlhelp.com/    http://enhanced-designs.com/
Received on Thursday, 9 April 1998 19:27:24 GMT

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