Re: Need some help (Alt te

        Reply to:   RE>>Need some help  (Alt text and descriptions)

Gregg's delineation of the different cases and solutions is right on target and conforms with much that we have learned through years of description for linear TV and their accompanying images.

He must think best just before sleep... :-)

- Larry

Larry Goldberg, Director
Media Access
WGBH Educational Foundation
125 Western Ave.
Boston, MA  02134
617-492-9258 (voice/TTY)
fax 617-782-2155
Internet:  Larry_Goldberg@WGBH.org


--------------------------------------
Date: 7/10/97 12:46 AM
To: Larry Goldberg
From: Gregg Vanderheiden
I'm trying to sort out what has been proposed as ideas and what is on the plate as far as new versions of HTML. So bear with me if I just talk of ideas here without referring to particular tags etc.


I concur that we want to have a single page that is displayable in a form appropriate to the user.

a) The user may want graphics
b) They may be able to see but still want no graphics (for speed)
c) They may be unable to see and want just quick access to the major information so they can navigate through a page. (e.g. they don't care about the graphics at all unless they are part of navigation)
d) They may want to know what the graphics look like, what a logo looks like, etc.

So we have a bunch of situations and we want to figure out the least amount of work and tagging that will meet the requirements.   

We also have different uses of graphics.

1)  A DECORATION - a decorative picture, a logo, something with no particular information value but which someone may want to know the description of.
2)  A LABEL/TITLE - a picture which does nothing (not a link) but serves as an identifier, a label, a title or some other information that is important to understanding the organization or purpose of the page or section of the page
3)  GRAPHIC PRESENTATION OF INFORMATION - this is information which is presented in graphic form.  Much more than a title, it would require multiple sentences to convey the information that is presented in this image.  And the information is not casual information (e.g. a logo which tries to depict something). But information which is central to understanding the information presented on the page.  Perhaps a chart or diagram.
4)  An ANCHOR - a graphic that is serving in place of anchor text for a link.  These anchors graphics sometimes ALSO serve functions 1, 2 , or 3 in addition to being an anchor.


For #1 most users just want to know what it is.  Something very short to describe it.  For example "IBM logo".  Or   "Nova Logo".   Someone may want to know what it looks like but most users don't want to waste viewing space (or download time?) with the description.

For #2 the exact meaning (though not necessarily the appearance) needs to be provided.  Again the description might be avail on request but not with the item.

For #3 The information presented in the graphic should be provided whenever the graphic is not.  (many may find it useful to have it along with the graphic, but it would usually be too long to be desired if the graphic were there)

For #4 It is important to know what the link is for.  Presumably this could be determined if you could see the graphic (though this is no always true).  What is needed here is the function or reference of the link.  HOWEVER, often this link ALSO has a function 1,2, or 3 attached... and the descriptions above would apply.


Figuring out what should go into an alt tag is pretty straightforward if you really think about it. But unfortunately what goes into the alt text is different in the different situations and we need to think of something that is easy to tell people.  We also need a mechanism for the longer descriptions.  

And we need to note that the longer descriptions take two forms.  One is just long descriptions of what something looks like that may be of interest to some people but is not of particular value to most. (e.g. #1 or #2 above)  The other type of long text is #3 above and would be of interest to anyone trying to understand a page.  But there is also the case where the function of the graphic is covered by the caption so a further description is not needed (or at least is not in the "needs to be there for the page to be understood" category.

Ooh.  Too many if and buts...


So What would we recommend that is effective yet simple and straightforward.  I'm thinking on paper a bit here so feel free to pick holes in this.

1) all images should have an ALT tag (perhaps we should change the name to FUNCTION tag) that would tell you the FUNCTION of the graphic.  (e.g.  "IBM Logo",  "Section Title: Banana Products",  "Graph of population vs age",  "Divider Line", "bullet" (though some say a bullet should just have an * for the alt text), "More Information", "Search Button", 

2) if an image is an anchor then the BROWSER should underline the ALT TEXT and color it just like it does any text anchor.

3) All images should have a PARALLEL FILE that is located next to the graphic file and has the same name as the graphic file except that the ending is .txt  or .dsc  .  (Alternately a DESC= tag could be used to indicate that there was a description file. The file could then have any name or location.   This would also allow the browser to provide some indication as part of the alt text that there was a description available for this graphic.  Perhaps a distinctive character could be added to the end of the alt text like a plus. )

4) all BROWSERS would have a command that could be issued while on a graphic to cause the text description file (see #3 just above) to be fetched and put into the document in the location of the Graphic (with square brackets around it).  (it would have to be something that was easily accomplished with a screen reader.)  Perhaps an "Alt Click" or "Control Click" on the alt text.   (If there was not description then the browser would beep.)


This format has the advantage that the person can call up the description of an image whenever they want but when they don't want the description (which would be most of the time if the alt text were any good) they don't have to use up display space or download time.     For the case where the description is important to understanding the information on the page, we would just emphasis that providing the description file critical.  


Well its too late now to think straight so let me toss this into the hopper for discussion.  I'm blurry brained right now so I'm sure I'm missing something.

Nite nite

Gregg

-- ------------------------------
Gregg C. Vanderheiden Ph.D.
Professor - Dept of Industrial Engineering
Director - Trace R & D Center, Waisman Center
University of Wisconsin- Madison
gv@trace.wisc.edu,    WWW&FTP at  Trace.Wisc.Edu
for a list of our Listserves send "index" to listproc@trace.wisc.edu




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Subject: RE: Need some help  (Alt text and descriptions)
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