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Re: Screen readers and images

From: David Woolley <david@djwhome.demon.co.uk>
Date: Sat, 10 Feb 2001 12:31:46 +0000 (GMT)
Message-Id: <200102101231.f1ACVk819786@djwhome.demon.co.uk>
To: w3c-wai-ig@w3.org
> 
> Can anyone explain to me how screen readers handle images?  I was under the
> impression that if an image doesn't have an alt tag, the screen reader would

alt is an attribute of the img element, not a tag.

alt is mandatory, so any handling of img without alt comes under the class
of error recovery and should not be an issue for page designers, only
for user agent designers.  Given the extent to which HTML invalidly
omits alt attributes, audio browsers ought to provide some indication
of the presence of the image.  Page designers should *never* miss out alt.

The correct way of indicating that an image has no useful purpose (to
someone who can't see it) is to use alt="".  This should not be used for
images that contain real information, as the user may just have images
off for faster browsing, or may only be partially blind or have a helper
who can describe images to them.  It should not be used where there is
a sensible alternative that matches the flow of the text (bullets should
be done with CSS and <li>, but failing that with alt="*").

Note that abuse of alt="" has resulted in some demand from Lynx users to
treat it as though alt were missing.

(If you have a reference to a URL from a page that is only in anchors
with images and no alt text, Lynx will put them into a "hidden links" 
section of the list, if you ask it for a list of all links on the page.)
Received on Saturday, 10 February 2001 08:35:14 GMT

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