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Thread: alt text and captions
Number of posts in this thread: 17 (In chronological order)
From: Rachel Tanenhaus
Date: Thu, Feb 05 2004 9:34AM
Subject: alt text and captions
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Hello!
I've got a question about graphics, alt text, and captions. Not
captions as in open- or closed-captioning, but captions as in the text
that sometimes occurs under pictures.
If a graphic is being used on a web site, and its caption is essentially
a description of the picture being shown, what should be in the alt
text? Right now, the caption and the alt text are identical, and we're
wondering if that's a usability issue, or if it's just plain redundant
and annoying, or what? How does one handle repetitive text like that?
I suspect that a blank alt attribute (<alt="">) is inappropriate.
Thanks in advance for your help, and please feel free to point me
somewhere if this has already been discussed (but I checked the recent
archives and didn't see it).
-Rachel
Rachel H. Tanenhaus, MPH
Information Specialist
New England ADA & Accessible IT Center
374 Congress Street, Suite 301
Boston, MA 02210
Phone: (617) 695-0085 (v/tty)
or (800) 949-4232 (v/tty) (in New England)
Fax: (617) 482-8099
E-mail: = EMAIL ADDRESS REMOVED =
URL: www.NewEnglandADA.org
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From: Jared Smith
Date: Thu, Feb 05 2004 10:02AM
Subject: Re: alt text and captions
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Rachel-
The key with alt text is to provide an equivalent alternative to the
non-text element. How that is done is up to you. The wording of WCAG
1.0 and Section 508 is, "Provide a text equivalent for every non-text
element (e.g., via "alt", "longdesc", or in element content)."
The key in your situation is "in element content". You are providing
the alternative to the image. So in your case, I would think that
alt="" is perfectly sufficient for the image, assuming that the
caption is in accessible text form on the page and not part of the image
itself.
Jared Smith
WebAIM (Web Accessibility In Mind)
Center for Persons with Disabilities
Utah State University
***************
On Thursday, February 05, 2004 you sent:
> Hello!
> I've got a question about graphics, alt text, and captions. Not
> captions as in open- or closed-captioning, but captions as in the text
> that sometimes occurs under pictures.
> If a graphic is being used on a web site, and its caption is essentially
> a description of the picture being shown, what should be in the alt
> text? Right now, the caption and the alt text are identical, and we're
> wondering if that's a usability issue, or if it's just plain redundant
> and annoying, or what? How does one handle repetitive text like that?
> I suspect that a blank alt attribute (<alt="">) is inappropriate.
> Thanks in advance for your help, and please feel free to point me
> somewhere if this has already been discussed (but I checked the recent
> archives and didn't see it).
> -Rachel
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From: Sachin Pavitran
Date: Thu, Feb 05 2004 10:19AM
Subject: Re: alt text and captions
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Hello Rachel,
Being a Jaws user, I don't think it would be redundant to have an ALT text
for the caption on the picture provided the caption on the picture is not a
text element by itself. If the text is something that's part of the picture
it would be essential to have a ALT text so that the screen reader know what
the information was on the picture.
I hope this makes sense.
Regards.
******************************************************
Sachin Dev Pavithran
Training and Development Specialist
Center for Persons with Disabilities
6800 Old Main Hill,
Logan, Ut - 84322
U.S.A.
Work Phone : 1-(435)-797 0974
Email : = EMAIL ADDRESS REMOVED =
Visit Us at http://www.cpd.usu.edu
******************************************************
----- Original Message -----
From: "Rachel Tanenhaus" < = EMAIL ADDRESS REMOVED = >
To: < = EMAIL ADDRESS REMOVED = >
Cc: "'Kathy Gips'" < = EMAIL ADDRESS REMOVED = >
Sent: Thursday, February 05, 2004 9:26 AM
Subject: alt text and captions
> Hello!
>
> I've got a question about graphics, alt text, and captions. Not
> captions as in open- or closed-captioning, but captions as in the text
> that sometimes occurs under pictures.
>
> If a graphic is being used on a web site, and its caption is essentially
> a description of the picture being shown, what should be in the alt
> text? Right now, the caption and the alt text are identical, and we're
> wondering if that's a usability issue, or if it's just plain redundant
> and annoying, or what? How does one handle repetitive text like that?
> I suspect that a blank alt attribute (<alt="">) is inappropriate.
>
> Thanks in advance for your help, and please feel free to point me
> somewhere if this has already been discussed (but I checked the recent
> archives and didn't see it).
>
> -Rachel
>
> Rachel H. Tanenhaus, MPH
> Information Specialist
> New England ADA & Accessible IT Center
> 374 Congress Street, Suite 301
> Boston, MA 02210
> Phone: (617) 695-0085 (v/tty)
> or (800) 949-4232 (v/tty) (in New England)
> Fax: (617) 482-8099
> E-mail: = EMAIL ADDRESS REMOVED =
> URL: www.NewEnglandADA.org
>
>
>
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> visit http://www.webaim.org/discussion/
>
>
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From: Rachel Tanenhaus
Date: Thu, Feb 05 2004 10:25AM
Subject: RE: alt text and captions
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Hello!
You make an excellent point, but no, the caption is not part of the
graphic. It's text. So JAWS users would have no problem accessing it.
-Rachel
Rachel H. Tanenhaus, MPH
Information Specialist
New England ADA & Accessible IT Center
374 Congress Street, Suite 301
Boston, MA 02210
Phone: (617) 695-0085 (v/tty)
or (800) 949-4232 (v/tty) (in New England)
Fax: (617) 482-8099
E-mail: = EMAIL ADDRESS REMOVED =
URL: www.NewEnglandADA.org
From: Christopher Phillips
Date: Thu, Feb 05 2004 10:49AM
Subject: Re: alt text and captions
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Rachel,
It seems to me that the purpose of a caption is generally to provide
some type of commentary or explanation
of an image, not a description of the image itself. If the caption is
simply repeating with text the exact same
information that the image is presenting, then is it really necessary?
For example, an appropriate alt tag may
be 'Picture of a young girl sitting at a desk and typing on a computer'
and a caption for that picture may be 'Here
we can see Elizabeth working on her english assignment.' The alt tag
wouldn't be appropriate to use as the
caption, nor the other way around. While I'm sure there are exceptions
to this, it seems that most of the time
the alt tag should provide a description of the image and the caption
can then assign further meaning to what
the alt tag has described.
Christopher Phillips
Institute for Community Inclusion
100 Morrissey Blvd.
Boston, MA 02125
Curb Cut Learning
http://www.communityinclusion.org/curbcut/
On Feb 5, 2004, at 10:18 AM, Rachel Tanenhaus wrote:
> Hello!
>
> You make an excellent point, but no, the caption is not part of the
> graphic. It's text. So JAWS users would have no problem accessing it.
>
>
> -Rachel
>
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From: Jukka K. Korpela
Date: Thu, Feb 05 2004 11:00AM
Subject: Re: alt text and captions
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On Thu, 5 Feb 2004, Rachel Tanenhaus wrote:
> If a graphic is being used on a web site, and its caption is essentially
> a description of the picture being shown, what should be in the alt
> text?
This depends on the content and the informational purpose of the image,
and might best be discussed in the context of a particular page.
And what does it mean that the caption is a description?
> Right now, the caption and the alt text are identical
That's hardly a good idea. It will result in the same text being spoken,
shown, or otherwise presented to the user.
For example, if the image is a photo of a person and the caption is his
name, then I would use alt="[photo of NN]" where NN is the name.
The bracket convention, used to indicate that the text is not really a
replacement but a description or reference, is far from universally
accepted, and might cause minor problems at times, but it sounds
reasonable to me.
Quite often the image and its caption would best be just omitted when
images cannot be displayed, but there's no way to achieve that, so it's
best to make the alt text some _indication_ that tells that the text to
come might relate to the image.
--
Jukka "Yucca" Korpela, http://www.cs.tut.fi/~jkorpela/
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From: julian.rickards
Date: Thu, Feb 05 2004 11:14AM
Subject: RE: alt text and captions
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The WAVE tool flags web pages where the alt text and adjacent text are
identical - perhaps this is more of a usability issue rather than an
accessibility issue but if the caption is the same as the alt text, those
with screen readers are going to hear the same text twice.
I would recommend either making one different from the other or use empty
alts.
I saw a similar issue whereby the title attribute had the same content as
the anchor text such as <a href="#" title="Home">Home</a> which again is
redundant.
---------------------------------------------------------
Julian Rickards
Digital Publications Distribution Coordinator
Publications Services Section
Ontario Ministry of Northern Development and Mines
Phone: (705) 670-5608
Fax: (705) 670-5690
>
From: Andrew Kirkpatrick
Date: Thu, Feb 05 2004 6:10PM
Subject: Re: alt text and captions
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Another possibility to consider is that it may be worthwhile to provide some
sort of image identifier in the alt text. If people are likely to be
discussing the page contents, they might refer to the images in the
discussion. The screen reader user would not have the same context clues as
the sighted user in this case so it could be worthwhile to mark the image
alt as (for example) "figure 1" and then the caption appearing after the
image could be "figure 1: net gain in productivity" (and in this case
there'd be a need for a longdesc also...).
AWK
>
>>
From: Tim Beadle
Date: Fri, Feb 06 2004 2:22AM
Subject: Re: alt text and captions
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On Thu, Feb 05, 2004 at 11:26:44AM -0500, Rachel Tanenhaus wrote:
> I've got a question about graphics, alt text, and captions. Not
> captions as in open- or closed-captioning, but captions as in the text
> that sometimes occurs under pictures.
Dan Cederholm at Simplebits.com did one of his Simplequizzes about this
recently:
http://www.simplebits.com/archives/2004/01/02/simplequiz_part_xi_image_floating.html
HTH,
Tim
--
"A fool chooses to starve himself and we choose to watch. One billion people
have no choice and we ignore them."
-- Placard beneath David Blaine's perspex box
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From: John Norgaard
Date: Fri, Feb 06 2004 2:42AM
Subject: RE: Use of Audio Interferes with Screenreaders?
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Hi Tom,
First I agree with not autostarting anything:)
But do not forget that the guidlines are what it is says - guidlines! At our
portal for blind children we have a lot of things that are not "allowed" but
works, because we have tested them with blind users (User Approved;).
When it comes to audio don't worry about Flash 5/Flash MX - there are no
differences in audio/sound.
One problem with using Flash and screenreader is ussually the sad fact than
when tabbing through an html page you get trapped when you tab into the
embeded flash/.swf - you can't get out.
You can download a solution for this problem we have made here (tab out of
flash extention):
http://www.sonokids.com/wwwsonokids/english/developers.html
An interesting use in your case of flash audio might be Hayden Porters
FlashSound API:
http://www.flashsoundapi.com/
//John
John Norgaard
Sonokids.com
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From: Andrew Kirkpatrick
Date: Fri, Feb 06 2004 6:39AM
Subject: RE: Use of Audio Interferes with Screenreaders?
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> One problem with using Flash and screenreader is ussually the
> sad fact than when tabbing through an html page you get
> trapped when you tab into the embeded flash/.swf - you can't get out.
This is not exactly accurate. With a screen reader you do not get trapped
because the screen reader mediates the tab order. Without a screen reader a
keyboard user would have this problem, but only if they are using the Flash
6 player or earlier.
The Flash 7 player addressed this issue, so the tab out of flash extension
is not needed if you can reasonably expect that users will have the Flash 7
player.
> You can download a solution for this problem we have made
> here (tab out of flash extention):
> http://www.sonokids.com/wwwsonokids/english/developers.html
The tab out of flash extension is a great tool that has been good to have
around and has not yet outlived its usefulness.
AWK
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From: John Norgaard
Date: Fri, Feb 06 2004 6:54AM
Subject: Re: Use of Audio Interferes with Screenreaders?
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>> One problem with using Flash and screenreader is ussually the
>> sad fact than when tabbing through an html page you get
>> trapped when you tab into the embeded flash/.swf - you can't get out.
>
> This is not exactly accurate. With a screen reader you do not get trapped
> because the screen reader mediates the tab order. Without a screen reader a
> keyboard user would have this problem, but only if they are using the Flash
> 6 player or earlier. The Flash 7 player addressed this issue
You are right - Guess I was more thinking of visual impaired using
magnifying tools, and also would like a speech.
And on a Mac - The Flash Player 7 still traps you. I know a Mac might not be
the common machine for visual impaired, but still:)
//John
John Norgaard
sonokids.com
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From: julian.rickards
Date: Mon, Feb 09 2004 8:18AM
Subject: RE: alt text and captions
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In advanced browsers that support CSS generated content, this type of code
may eliminate the need for both alt and caption text.
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Strict//EN">
<html>
<head>
<title>Untitled</title>
<style type="text/css">
<!--
img:after {
content: attr(alt);}
-->
</style>
</head>
<body>
<img src="scenic.jpg" alt="This is a scenic photograph" width="406"
height="273">
</body>
</html>
I can't show you the results. It is my understanding that only Opera 7+ and
Safari supports this. For those who can't see the results, the content:
attr(alt); displays the content of the alt attribute as text right beside
the image and with additional styling, fonts, colors, alignment and other
properties may be applied. I have also seen content from the <title> tag
displayed within the browser window but I can't remember the details of how
it was done - something very similar but it pulled the content from the tag,
not just an attribute.
Idea came from: http://www.literarymoose.info/=/synopsis/violate.xhtml, near
the bottom are Floated Generated Content and Positioned Generated Content.
---------------------------------------------------------
Julian Rickards
Digital Publications Distribution Coordinator
Publications Services Section
Ontario Ministry of Northern Development and Mines
Phone: (705) 670-5608
Fax: (705) 670-5690
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From: Giorgio Brajnik
Date: Tue, Feb 10 2004 2:11AM
Subject: RE: alt text and captions
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I don't think it is a good idea to put this kind of content into css
rather than as an attribute in HTML. This kind of content is an
essential part of the page (it's not just style) and therefore it has
to be reachable (visible or audible) in the same way the rest is. If you
put it in CSS then all the devices that can't read CSS won't be able
to render it (for example lynx, Blazer on PALM OS, GoogleBot, etc.).
Regards,
Giorgio Brajnik
______________________________________________________________________
Dip. di Matematica e Informatica | voice: +39 (0432) 55.8445
Universita` di Udine | fax: +39 (0432) 55.8499
Via delle Scienze, 206 | email: = EMAIL ADDRESS REMOVED =
Loc. Rizzi -- 33100 Udine -- ITALY | http://www.dimi.uniud.it/~giorgio
= EMAIL ADDRESS REMOVED = said:
> In advanced browsers that support CSS generated content, this type
of code
> may eliminate the need for both alt and caption text.
>
> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Strict//EN">
> <html>
> <head>
> <title>Untitled</title>
> <style type="text/css">
> <!--
> img:after {
> content: attr(alt);}
> -->
> </style>
>
> </head>
> <body>
> <img src="scenic.jpg" alt="This is a scenic photograph" width="406"
> height="273">
> </body>
> </html>
>
> I can't show you the results. It is my understanding that only
Opera 7+ and
> Safari supports this. For those who can't see the results, the content:
> attr(alt); displays the content of the alt attribute as text right
beside
> the image and with additional styling, fonts, colors, alignment and
other
> properties may be applied. I have also seen content from the
<title> tag
> displayed within the browser window but I can't remember the
details of how
> it was done - something very similar but it pulled the content from
the tag,
> not just an attribute.
>
> Idea came from:
http://www.literarymoose.info/=/synopsis/violate.xhtml, near
> the bottom are Floated Generated Content and Positioned Generated
Content.
>
> ---------------------------------------------------------
> Julian Rickards
> Digital Publications Distribution Coordinator
> Publications Services Section
> Ontario Ministry of Northern Development and Mines
> Phone: (705) 670-5608
> Fax: (705) 670-5690
>
>
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From: Tim Beadle
Date: Tue, Feb 10 2004 2:59AM
Subject: Re: alt text and captions
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On Tue, Feb 10, 2004 at 10:02:49AM +0100, Giorgio Brajnik wrote:
> I don't think it is a good idea to put this kind of content into css
> rather than as an attribute in HTML. This kind of content is an
> essential part of the page (it's not just style) and therefore it has
> to be reachable (visible or audible) in the same way the rest is. If you
> put it in CSS then all the devices that can't read CSS won't be able
> to render it (for example lynx, Blazer on PALM OS, GoogleBot, etc.).
The *content* isn't in the CSS; it's in the HTML as an attribute of the image.
It's the display of the content that's being handled by CSS, which IMHO is
just one of the many great things that CSS can do. Lynx et al will render the
alt text as normal.
Another example is for displaying blockquotes, but this time using javascript:
http://www.1976design.com/blog/archive/2003/11/10/updates/
Also, displaying image captions using js:
http://www.1976design.com/blog/archive/2003/11/25/captions/
*None* of these methods rely on javascript for their content; they are just
progressive enhancement methods on top of the structural markup. More capable
user agents get the stuff they can handle, while less-capable ones get the
HTML.
A great article on progressive enhancement:
"Keep it Simple: The Behavior Layer" by Peter-Paul Koch
[http://digital-web.com/columns/keepitsimple/keepitsimple_2004-01.shtml]
Cheers,
Tim
--
"Internet Explorer is like a box of chocolates. You never know what you're
gonna get." -- Sjors
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From: Dierickx, Len
Date: Tue, Feb 10 2004 7:11AM
Subject: RE: alt text and captions
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Dear,
Most of the attributes can be shown with CSS2 in Opera, like alt attributes
for images but access keys as well.
Title attributes for abbreviations even the language in HTML tag.
Opera provides a user stylesheet where these options are used. (User mode >
Accessibility lay-out).
>The *content* isn't in the CSS; it's in the HTML as an attribute of the
image.
This is true for the img example but CSS2 provides a possibility to add text
using rules in the stylesheet like this:
A:after{content:" Provide a meaningful title.";}
The content is in the CSS file.
This can be useful but I would prefer that the content remains in the HTML
file because stylesheets can be disabled.
That way the content would never reach the HTML file and would not be
accessible for text browsers.
I use both techniques, revealing attributes and adding content via the
stylesheet, for showing accessibility problems with a webpage. I created a
testing style sheet with these CSS2 and CSS3 possibilities.
You can find it at http://www.none.be/css/myAccessibility.css
It shows several Alt and Title attributes, testing for nested tables and
several other things.
Please note that this will only work with Opera7 or Mozilla1.6.
If you don't know how to add a userstylesheet, check out the css-wicki page
about Opera userstylesheets.
http://css-discuss.incutio.com/?page=OperaUserStylesheets
--
Kind regards,
Len Dierickx
http://www.none.be
From: julian.rickards
Date: Tue, Feb 10 2004 7:49AM
Subject: RE: alt text and captions
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I know that content may be added to as you had shown in your example:
img:after {content: "additional content: ")
and I too agree that content should be in the HTML, not in the CSS as in my
example above. The technique I demonstrated simply made existing content in
the HTML more visible. As many of you know, the tooltip behaviour of IE with
regard to Alt text is contrary to the HTML guidelines but for those users,
this behaviour does allow them to see the alt text in addition to the
graphic.
The reason I thought this technique and CSS property might be of interest is
that it allows captioning without any additional content.
---------------------------------------------------------
Julian Rickards
Digital Publications Distribution Coordinator
Publications Services Section
Ontario Ministry of Northern Development and Mines
Phone: (705) 670-5608
Fax: (705) 670-5690
>