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Thread: latest practice on alt text
Number of posts in this thread: 9 (In chronological order)
From: Angela French
Date: Tue, Dec 23 2008 12:10PM
Subject: latest practice on alt text
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I am looking for any research on the use of alternative text for images on web pages that are merely for illustration purposes only.
Specifically, does it just create "aural clutter" to provide alternative text on images that impart no information? Is a page more usable to a screen reader user if alt text is left out under such circumstances?
Any opinions appreciated.
Angela French
Internet Specialist
State Board for Community & Technical Colleges
360-704-4316
http://www.checkoutacollege.com
http://www.sbctc.ctc.edu
From: Patrick H. Lauke
Date: Tue, Dec 23 2008 12:15PM
Subject: Re: latest practice on alt text
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Angela French wrote:
> I am looking for any research on the use of alternative text for images on web pages that are merely for illustration purposes only.
> Specifically, does it just create "aural clutter" to provide alternative text on images that impart no information? Is a page more usable to a screen reader user if alt text is left out under such circumstances?
alt=""
--
Patrick H. Lauke
From: Jukka K. Korpela
Date: Tue, Dec 23 2008 12:20PM
Subject: Re: latest practice on alt text
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Angela French wrote:
> I am looking for any research on the use of alternative text for
> images on web pages that are merely for illustration purposes only.
I don't think there's any recent new information on it - or even that
research is needed. It's a matter of common sense and becomes obvious as
soon as you think about the meaning and possible uses of alt texts: they are
supposed to appear, and they usually do appear, in place of an image when
the image is not displayed.
> Is a page
> more usable to a screen reader user if alt text is left out under
> such circumstances?
It is never correct to omit the alt attribute. It is correct to use alt=""
(or, in some cases, alt=" ") for an image that is purely decorational and
has no meaningful nonvisual substitute.
There are difficult problems with alt texts (see
http://www.cs.tut.fi/~jkorpela/html/alt.html for some discussions), but
decorative images are simple - except in the sense that many people have
weird ideas of alt texts and they even think they are accessibility-oriented
when they type alt="decorative image" or alt="nice butterflies".
--
Yucca, http://www.cs.tut.fi/~jkorpela/
From: Debbie Pomerance
Date: Tue, Dec 23 2008 5:00PM
Subject: Re: latest practice on alt text
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On Tue, Dec 23, 2008 at 2:17 PM, Jukka K. Korpela < = EMAIL ADDRESS REMOVED = >wrote:
> Angela French wrote:
>
> > I am looking for any research on the use of alternative text for
> > images on web pages that are merely for illustration purposes only.
>
> I don't think there's any recent new information on it - or even that
> research is needed. It's a matter of common sense and becomes obvious as
> soon as you think about the meaning and possible uses of alt texts: they
> are
> supposed to appear, and they usually do appear, in place of an image when
> the image is not displayed.
>
> > Is a page
> > more usable to a screen reader user if alt text is left out under
> > such circumstances?
>
> It is never correct to omit the alt attribute. It is correct to use alt=""
> (or, in some cases, alt=" ") for an image that is purely decorational and
> has no meaningful nonvisual substitute.
>
> There are difficult problems with alt texts (see
> http://www.cs.tut.fi/~jkorpela/html/alt.html<;http://www.cs.tut.fi/%7Ejkorpela/html/alt.html>;for some discussions), but
> decorative images are simple - except in the sense that many people have
> weird ideas of alt texts and they even think they are
> accessibility-oriented
> when they type alt="decorative image" or alt="nice butterflies".
>
> --
>
Not using alt="nice butterflies" I understand is silly, but why not
alt="decorative image" to denote an image on the page, that is not
substantive, so the non-sighted viewer knows that it is not material to the
sense of the page? I have a logo on my page, should I not give an alt
designation of "company logo" ?
Thank you.
Debbie P.
--
Debbie Pomerance
mailto = EMAIL ADDRESS REMOVED =
Microsoft: "You've got questions. We've got dancing paperclips."
For Net security use Unix, Linux, any 'ix' OS.
From: Benjamin Hawkes-Lewis
Date: Tue, Dec 23 2008 5:30PM
Subject: Re: latest practice on alt text
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On 23/12/08 23:56, Debbie Pomerance wrote:
> Not using alt="nice butterflies" I understand is silly, but why not
> alt="decorative image" to denote an image on the page, that is not
> substantive, so the non-sighted viewer knows that it is not material to the
> sense of the page?
Screen readers would typically render <img alt="decorative image"> as
"image decorative image", which slows down the user's processing of the
page.
Screen readers will typically not render <img alt=""> at all, so it
doesn't clog up the user experience.
> I have a logo on my page, should I not give an alt
> designation of "company logo" ?
A company logo probably isn't an example of a _purely_ decorative image.
I don't think it's possible to generalize about appropriate alternative
text for logos, because they are used for particular purposes in
particular contexts.
Consider the following two simple scenarios:
(A) <h1><img src="shell.jpg" alt="{ALTERNATIVE}">Shell Oil</h1>
(B) <h1><img src="shell.jpg" alt="{ALTERNATIVE}"></h1>
I'd suggest:
(A) <h1><img src="shell.jpg" alt="">Shell Oil</h1>
(B) <h1><img src="shell.jpg" alt="Shell Oil"></h1>
- and perhaps putting a description of the logo itself somewhere in an
About section.
Note that preferred text alternatives for logo images is the subject of
one of the questions in the WebAIM screen reader survey.
--
Benjamin Hawkes-Lewis
From: Jared Smith
Date: Tue, Dec 23 2008 9:35PM
Subject: Re: latest practice on alt text
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On Tue, Dec 23, 2008 at 5:25 PM, Benjamin Hawkes-Lewis
< = EMAIL ADDRESS REMOVED = > wrote:
> A company logo probably isn't an example of a _purely_ decorative image.
And the logo is typically a link - and linked images should never have
missing alt attribute or null/empty alt text.
> Note that preferred text alternatives for logo images is the subject of
> one of the questions in the WebAIM screen reader survey.
Of course full data and analysis will come later, but with over 750
responses so far, I can definitively say that there is absolutly no
consensus from screen reader users on what they prefer as alternative
text for logo images. :-)
Jared Smith
WebAIM
From: Jukka K. Korpela
Date: Wed, Dec 24 2008 5:00AM
Subject: Re: latest practice on alt text
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Benjamin Hawkes-Lewis wrote:
> A company logo probably isn't an example of a _purely_ decorative
> image.
At least it shouldn't, though some people decorate their pages with company
logos improperly.
> I don't think it's possible to generalize about appropriate
> alternative text for logos, because they are used for particular
> purposes in particular contexts.
However, we can generalize about appropriate alternative text for logos by
their purpose. After all, an alt text should is not really about an image;
instead, it is supposed to do the same job as the image does, as far as
possible.
Typically a logo is used on all pages of an organization as an indication of
their belonging to a particular site of a particular organization. It is
like an owner's mark. If it is not a link, then one could consider using alt
text like "ACME logo", even though this is somewhat silly in a sense: a logo
is a visual concept, and the alt text is supposed to work even for people
who were born bild. Yet, some visual concepts are so commonly known that we
might justify their use. In principle, "This is a web page by ACME." would
express the intended message explicitly and with no implication of visual
concepts, but I admit it might be a bit too puristic to require such usage.
If a logo, used as "owner's mark", as it often is and often should, then the
word "logo" becomes strange and even misleading. Using just the
organization's name or abbreviation, like "ACME", is preferable. After all,
the alt text acts as link text here, and it should thus reflect the content
of the
> (A) <h1><img src="shell.jpg" alt="{ALTERNATIVE}">Shell Oil</h1>
In this scenario, the image is presumably not a logo in the strict sense of
the word, i.e. a name or abbreviation in a particular established style, but
an image that otherwise symbolizes something, either as such or when used in
conjunction with a text or a logo. It is not purely decorative then, but
then it is adequate to use alt="" when it as accompanied with a name or
abbrevation; otherwise, when it is used alone and it is assumed to act as a
visual symbol referring to an organization, it should be be similarly to a
logo (in the case of Shell, I would probably use "Shell company", since
"Shell" alone is not clear enough in meaning).
> - and perhaps putting a description of the logo itself somewhere in an
> About section.
That's highly questionable. Organizations may think that their logos are
interesting as such (after all, their design may have been very expensive
and they may have considerable commercial value), but to a visitor who does
not see a logo, could it really matter what it looks like, as apart from
what it symbolizes? It might be of some interest to people who do see it,
but then this has nothing to do with alt attributes.
--
Yucca, http://www.cs.tut.fi/~jkorpela/
From: Patrick H. Lauke
Date: Wed, Dec 24 2008 6:25AM
Subject: Re: latest practice on alt text
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Jukka K. Korpela wrote:
>> - and perhaps putting a description of the logo itself somewhere in an
>> About section.
>
> That's highly questionable. Organizations may think that their logos are
> interesting as such (after all, their design may have been very expensive
> and they may have considerable commercial value), but to a visitor who does
> not see a logo, could it really matter what it looks like, as apart from
> what it symbolizes? It might be of some interest to people who do see it,
> but then this has nothing to do with alt attributes.
Agree completely. I'd say the only time an actual description of the
logo (in an alt attribute, or as actual text adjacent to it) could be
warranted is on a page/site discussing the graphic design of logos,
where the design/look itself are the actual content being discussed.
P
--
Patrick H. Lauke
From: Benjamin Hawkes-Lewis
Date: Wed, Dec 24 2008 9:40AM
Subject: Re: latest practice on alt text
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On 24/12/08 12:00, Jukka K. Korpela wrote:
> could it really matter what it looks like, as apart from
> what it symbolizes?
Well, yes, but that's what I'd envisage a description might actually
talk about: what are the visual components of the logo intended to mean?
Some (maybe most) logos don't symbolize anything much, so there wouldn't
be anything to say.
On the other hand, some logos are subjects of symbolic or historical
interest in their own right, for example the US Department of Justice seal:
Image: http://www.usdoj.gov/criminal/cybercrime/dojseal.gif
Discussion: http://www.usdoj.gov/jmd/ls/dojseal.htm
That is: if a discussion of the logo is in order, it's potentially
relevant to anyone, but doesn't belong on every page in an ALT attribute.
--
Benjamin Hawkes-Lewis
