Re: ALT Text Notes and Guidelines (take 2)

I have concern over strategy #2 being the prefered strategy.  Strategy #2
is the most elegant from a programming standpoint.  My main concern with #2
is visibility of the text description, which I beleive is important for
people to know it's there.  Especially for non-disabled peers not familiar
with disability access options helping a person with a disability to learn
to use a browser.  Strategy #1 is the most visible to people.  Strategy #2
is going to be highly dependent on browser implementation and I don't know
how consistent browser developers will be in rendering the ALTSRC
information or easy it will be to configure it to render ALTSRC
information, since it will be a little used function by the general public
(just try turning off images in Netscape 4.01, if you know how let me know).  
 
One solution would be for the browser recommendation to automatically
create the D tag if the ALTSRC field is present in the image.  This would
allow strategy #1 and #2 to be identical to end users.   

Jon

At 12:57 AM 7/17/97 -0500, you wrote:
>Here is an attempt to capture some of the comments made on this recently.
>
>This is still rough but perhaps less so than last time.
>
>Comments welcome 
>
>Gregg
>
>
>
>
>
>
>TYPES OF GRAPHIC USE (SIMPLE MODEL)
>Remember it is not what the graphic is but how it is used that determines
which category it falls in.  (These categories are NOT necessarily EXCLUSIVE)
>
>
>1)  as DECORATION -  Something with no particular information value in
understanding the intent and content of the page but which someone may want
to know the description of.   
>        Example: a decorative picture, a colored bar at the top of a page,
something to make layout prettier but which does not provide document
organizational information, etc may fall in this category.  
>
>
>2)  as LABEL/TITLE/STRUCTURE - 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
>       Examples:  
>
>
>3)  as 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 showing
people surrounding a world), but information which is central to
understanding the information presented on the page.  
>        Examples:  A chart or diagram.
>
>
> 4)  as 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.   [ Note: anchors are different from Uses
1,2,and 3 in that they exist in their own context and information about
the anchor target for instance could be conveyed within the <A> itself
rather than in the graphics context (e.g. using TITLE, or REL) ]
>
>
>NOTE: Animated graphics would be handled in the same manner as other
graphics unless they are long enough to constitute a movie.  Then they
should have time synched descriptions.
>
>
>
>
>
>ROUGH DRAFT SET OF COOPERATIVE ACCESS GUIDELINES (FOR BOTH WEB PAGE
CREATORS AND BROWSER DESIGNERS)
>
>PAGE CREATOR GUIDELINES
>
>P1)  ALT TEXT 
>     All images should have an ALT tag that would tell you the FUNCTION of
the graphic.  
>       Examples:  "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"
>       Note: There is not a consensus on whether ALT="" should be used.
It works well for some browsers such as Lynx but not for others like
Netscape or IE where it just behaves just like no alt text leaving an
unexplained graphic symbol on the page. 
>
>
>P2) TEXT DESCRIPTION
>All images should have a SEPARATE TEXT DESCRIPTION.  This is in addition
to, and separate from, the Alt text.  This text description of the graphic
can be stored in one (or more) of the following places:
>        1) The descriptive text can be stored on a separate html page.  A
link to the description can be placed next to the image.  It is suggested
that a Capital D be used as the anchor text for the link to this text.
(this technique is known as the D-Tag or D-Link technique.  [Notes: It
works today.  It works with all browsers. Some view this as a temporary
technique until other techniques such as those listed below are implemented
and supported by browsers]
>        2) The descriptive text could be stored in a PARALLEL FILE that is
stored separately from the graphic file.  An ALTSRC= tag could be used to
indicate that there was a description file. The file could have any name or
location.   [Notes: This technique requires that the browser support the
ALTSRC feature.  The browser would provide some indication to the user 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 "+".]
>        3) The description could be included as part of the graphic file
if the graphic file format supports this.  PNG for example does.  [Notes:
This technique requires the use of PNG or other graphic file format that
supports text. It also requires the browser to support the technique (as in
strategy #2).  It can be used in conjunction with strategy two.] [It would
be best if there were a way for the user to request the text portion of a
PNG file without downloading the full graphic file]
>	[General Note:  Strategy 2 seems to be the most flexible.  It works with
all graphic formats.  It is similar in structure the format suggested for
audio files]
>
>P3) DESCRIPTION OF VIDEO OR ANIMATION
>All video sequences should be accompanied by an auxiliary audio track
which includes a description of the important aspects of the video
presentation.  If the video player allows mixing of audio then the track
could be mixed with the regular audio track.  If mixing is not provided
then the auxiliary audio track should include both the description and the
regular audio track. 
>       NOTE: not all video or animation formats have audio.  Not all allow
multiple audio tracks.  An interesting thought would be to support parallel
audio track that could be merged and time synched with a video or animation
when it is played.   This would be similar to the strategy being suggested
for captioning.
>
>
>
>
>BROWSER DESIGN GUIDELINES
>
>B1) UNDERLINE ALT TEXT IF IT IS AN ANCHOR
>if an image is an anchor then the browser should underline the ALT TEXT
and color it just like it does any text anchor.  (Otherwise there is no way
to tell a passive-graphic from a graphic-link.)
>
>B2) INDICATE AND PULL UP LONG DESCRIPTIONS OF GRAPHICS ON COMMAND
>All browser should have a command that could be issued (while the user is
on a graphic), to cause the long text description file (see P2 above) to be
fetched and put into the displayed document at the location of the Graphic
(with square brackets around it).  If there was not a long description
available for the graphic then the browser would signal the user (beep?).
>        NOTE: the command would have to be something that was easily
accomplished with a screen reader. - Perhaps an "Alt Click" or "Control
Click" on the alt text.   
>
>
>B99) OPTION TO SUPPRESS DECORATIVE GRAPHICS
>There could be a user option which would tell the browser to suppress (or
not show) images that are marked as decorative only.   
>        Note:  I'll suggest this here for discussion, but I think that it
may be asking for something which is not a very big problem.   It adds to
browser complexity.  And decorative graphics make up only small part of
pages.  If they are properly labeled with short alt text they can be
quickly skipped over.   Most page designers are likely to label only a
small number of graphics on their pages as purely decorative anyway.
This also requires that there be a way to specify that a graphic is
decorative only... which is more work for page designers.   I think we
should focus page designers on more central issues.   
>
>
>
>I note that we have focussed on the Graphic only in this particular
thread.  We need a similar set for Audio information.  I'll try that in a
parallel memo to get ideas and input.
>
>
>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
>
>
>
>
> 
>
Jon Gunderson
Coordinator of Assistive Communication and Information Technology
Division of Rehabilitation - Education Services
University of Illinois at Urbana/Champaign
1207 S. Oak Street
Champaign, IL 61820

Voice: 217-244-5870
Fax: 217-333-0248
E-mail: jongund@uiuc.edu
WWW:	http://www.staff.uiuc.edu/~jongund
	http://www.als.uiuc.edu/InfoTechAccess

Received on Thursday, 17 July 1997 10:13:16 UTC