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

From: Jon Gunderson <jongund@uiuc.edu>
Date: Mon, 21 May 2001 08:38:35 -0500
Message-Id: <>
To: duerst@w3.org, Ian Jacobs <ij@w3.org>, clilley@w3.org
Cc: w3c-wai-ua@w3.org, w3c-i18n-ig@w3.org
I am not sure I would like a standard based on pixels, since this seems too 
connected to the hardware which is typically not under the control of the 
user agent developer.  Although a user agent developer could probably 
calculate this information.  I would like to see something more in the 
lines of point sizes, like 9 points as a minimum.

Does the concept of point size translate to other languages?

What terminology do non-Latin based languages use to indicate the size of 
their characters when rendered by a compuer?

Thanks for your help,

At 03:49 PM 5/21/2001 +0900, Martin Duerst wrote:
>Hello Ian,
>Just a few thoughts:
>- There is two issues of resolution, namely a) the screen resolution
>   (in pixels) and b) the visual resolution (in terms of optical frequency
>   per degree angle measured from they eye.
>   For a), certain scripts may need more pixels for character height
>   (or width) than others. As the Latin script is rather at the lower
>   end (for upper-case only, a height of 5 pixels is enough), you won't
>   get i18n problems, I guess (e.g. if the details for your checkpoint
>   say: "...control...size...of text down to at least 5 pixels...",
>   then that won't make it impossible for other scripts to get to their
>   smallest feasible size). In other words, a tight (i.e. as high as
>   possible) lower bound requirement can differ for different scripts,
>   but you can just take the minimum, and the minimum for Latin is a
>   good overall minimum.
>   b) is more difficult, because the UA software doesn't really control it.
>- Being able to increase the reference size of rendered text can also be
>   an I18N issue, as for some scripts, you really want to make the reference
>   size larger.
>- The hight should be the overall hight, not the x-height. The aspect
>   ratio doesn't have anything to do with it as far as I understand.
>- Please note that there are programs (mostly layout software such
>   as pagemaker,...) that show a line of text below a certain size as
>   a grey strip. This is called 'greek text' (as always, typographers
>   use strange terms :-). This can be quite helpful to get an overview
>   of a large page, less disturbing that actual text that is too small
>   to be read, but I'm not sure it's an accessibility issue.
>Regards,  Martin.
>At 11:21 01/05/18 -0400, Ian Jacobs wrote:
>>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] starts:
>>   "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
>>[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

Jon Gunderson, Ph.D., ATP
Coordinator of Assistive Communication and Information Technology
Division of Rehabilitation - Education Services
College of Applied Life Studies
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
WWW: http://www.w3.org/wai/ua
Received on Monday, 21 May 2001 09:38:00 UTC

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