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RE: [Issue 512] Seeking lower bound on text size requirement

From: Denis Anson <danson@miseri.edu>
Date: Tue, 22 May 2001 08:35:41 -0400
To: "'Richard Schwerdtfeger'" <schwer@us.ibm.com>, "'Ian Jacobs'" <ij@w3.org>
Cc: <clilley@w3.org>, <duerst@w3.org>, <w3c-wai-ua@w3.org>, <w3c-wai-ua-request@w3.org>
Message-ID: <000401c0e2bb$b6928030$17dcc241@deniscomputer>

The problem here is that this restriction is based on the low-resolution
of the television, which is a function of interlacing the drawing.

A real issue there is that text resolution may differ in different
platforms.  There are two ways to deal with things that are below the
resolution of a platform: render anyway, knowing that the user won't be
able to read the text (possibly by "greeking"), or to change the
formatting of text so that it meets the resolution of a specific

To provide access to all content, the second approach is preferable, but
can we say that you have to know what the "lower limit" will be?
Obviously, it would make no sense to say that browsers must provide all
fonts down to 18 point, or display all text at a minimum of 18 points.
This would not meet the needs of the computer based, or PDA based
browser.  But saying that you have to render down to 6 point font won't
make sense to a WebTV appliance.

On the other hand, a browser manufacturer probably knows the platform
that is being targeted.  IE for Windows won't be running on a WebTV
platform, and AvantGo for Palm won't be running on a PC.  It might be
the better part of valor to deal with the issue by saying that you must
render text in a minimum size that is readable based on the resolution
of the target platform for the browser.  This will be different for
different types of browser.  The upper limit of text size is also a
function of the display resolution of a browser, since a display size
that cannot show an entire letter at once would not be useful.

Denis Anson, MS, OTR/L
Assistant Professor
College Misericordia
301 Lake St.
Dallas, PA 18612

-----Original Message-----
From: w3c-wai-ua-request@w3.org [mailto:w3c-wai-ua-request@w3.org] On
Behalf Of Richard Schwerdtfeger
Sent: Friday, May 18, 2001 4:43 PM
To: Ian Jacobs
Cc: clilley@w3.org; duerst@w3.org; w3c-wai-ua@w3.org;
Subject: Re: [Issue 512] Seeking lower bound on text size requirement


Here is an interesting comment on digital TV text size

Here they talk about text no larger than 18 points.  ... might want to
say something about this in the techniques.


Rich Schwerdtfeger
Senior Technical Staff Member
IBM Accessibility Center
Research Division
EMail/web: schwer@us.ibm.com

"Two roads diverged in a wood, and I -
I took the one less traveled by, and that has made all the difference.",


                    Ian Jacobs

                    <ij@w3.org>           To:     clilley@w3.org,
                    Sent by:              cc:     w3c-wai-ua@w3.org

                    w3c-wai-ua-requ       Subject:     [Issue 512]
Seeking lower bound on text size requirement     




                    10:21 AM



Chris, Martin,

The UAWG would like your input on a question of visual text rendering
and internationalization. Checkpoint 4.1 of the 9 April 2001 draft [1]

  "4.1 Allow global configuration and control over the reference
       size of rendered text ..."

This is a Priority 1 checkpoint. One reviewer pointed out that it is not
really a P1 requirement to allow the user to choose very small text
sizes. Indeed, the intention of this checkpoint is primarily to allow
users with low vision to increase text size. [I would note here that
small text is useful to some users (e.g., so that users with screen
readers can scroll less), but that's not a P1 requirement.]

At our teleconference yesterday we asked ourselves whether we could come
up with some lower bound on the requirement. Thus, user agents would not
be required to provide access to very small text size as part of meeting
this checkpoint (or, for example, they might allow configuration, but
not actually be required to render very small text).

Our questions are thus:

 - How might we express a lower bound in text size?
   What units would we use? What parameter to measure
   size (x-height? aspect ratio?)?

 - What internationalization issues enter into this
   discussion? Does a lower bound requirement
   make sense across different scripts?

Thank you for your help on this topic,

 - Ian

Note to the Working Group: For checkpoints 4.1 and 4.2, we should change
"rendered text" to "visually rendered text" to be more precise.

[1] http://www.w3.org/TR/2001/WD-UAAG10-20010409/
[2] http://server.rehab.uiuc.edu/ua-issues/issues-linear-lc3.html#512

Ian Jacobs (ij@w3.org)   http://www.w3.org/People/Jacobs
Tel:                     +1 831 457-2842
Cell:                    +1 917 450-8783
Received on Tuesday, 22 May 2001 08:35:12 UTC

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