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Not described in words

From: Bailey, Bruce <Bruce.Bailey@ed.gov>
Date: Mon, 5 Mar 2007 08:31:46 -0500
Message-ID: <CCDBDCBFA650F74AA88830D4BACDBAB5130FA838@wdcrobe2m02.ed.gov>
To: "WCAG" <w3c-wai-gl@w3.org>

On the last call I expressed a concern that there is a gap between WCAG 2.0 SC 2.1.1 [1] and Section 508 1194.21(a) [2] because there are significant on-screen activities which cannot be "discerned textually" but still do not require "time-dependent analog input".  There was an action item to work on the definition of the latter [3], so any perceived gap will probably narrow, but this difference is not expected to be entirely eliminated.

The following examples are off the top of my head and may reflect an imperfect understanding of one or both terms.  For some, but not all, an alternative keyboard-oriented equivalent may be quite reasonable for a visually-oriented person who cannot use a mouse.  For others, the "time-dependent" aspect is only true if real world productivity is considered.  For all of these, I cannot imagine how to make them actually useable for someone who is blind.  I am at a loss for suggesting verbiage that splits the gap, but having gotten used to "discerned textually" over the last several years, I favor that term and I am quite comfortable that it is testable. 

Examples of activities that are not textually discernable but are digital and/or time-independent:

1. Centering a map on a particular point so that other features of interest are included in the view, or to correct the default positioning returned for a street address.

2. Cropping a photograph so that it is center on the subject or satisfies other criteria (like canvas size).

3. Adjusting the color balance, white point, or applying other variable effects to a photograph.

4. Identifying pupils in a photograph so that red-eye correction can be applied.

5. Assembling a puzzle, especially if the pieces can be rotated and are of odd sizes (so that any underlying grid arrangement is not obvious).

6. A simple paint program.

7. A complex vector drawing application.  (AutoCAD, as but one example in this genre, has amazing keyboard accessibility, but selecting objects without using a mouse equivalent remains tedious to the point of impracticality.)

8. A data visualization program that lets one manipulate data points in a cube as a means to facilitate pattern recognition.

My questions:
Can people think of other good examples that fall in this gap?
Is there really a gap?
Does it mater if there is?

Thanks!  Excepts from references follow.

[1] http://www.w3.org/WAI/GL/WCAG20/#keyboard-operation-keyboard-operable
All functionality of the content is operable through a keyboard interface without requiring specific timings for individual keystrokes, except where the underlying task requires time-dependent analog input.  [Level 1]

[2] http://www.access-board.gov/sec508/standards.htm#Subpart_b
When software is designed to run on a system that has a keyboard, product functions shall be executable from a keyboard where the function itself or the result of performing a function can be discerned textually.

[3] http://www.w3.org/WAI/GL/WCAG20/#analog-tim-dep-inputdef
input whose result is different depending on the rate of the analog movement (such as when line width varies with pen speed or pressure).
	Note:  Most actions carried out by a pointing device can also be done from the keyboard (for example, clicking, selecting, moving, sizing).  However, there is a small class of input that is done with a pointing device that cannot be done from the keyboard in any known fashion.  This type of input can be best characterized by the fact that the outcome can only be achieved by moving the pointer in a smooth fashion at a certain rate.  For example, in a watercolor program stroke width and transparency may depend on the rate of movement (and/or pressure) of a "brush."  Another example would be a real-time helicopter flight simulator.
Received on Monday, 5 March 2007 13:31:55 GMT

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