Functions or outcomes that can be expressed in words

At last Thursday's telecon we discussed Gregg's proposed definition of 
"Functionality or outcome can be expressed in words" [1] and thought the 
proposal felt more like a good example than a definition. I took an action 
to summarize our discussion and propose a modified definition.

<proposal>
If a function or outcome can be expressed in words, there are discrete 
values that can be labeled.  Functions that can not be expressed in words 
either 1. require a gesture or mouse movement that can not be emulated via 
a keyboard or 2. contain so many possible discrete values that operating 
with a keyboard becomes undesirable.  Outcomes that can not be expressed in 
words [are made up of] qualitative information such that each person 
attempting to describe it would say something different.
- Examples of functions that can not be expressed in words:  1. using the 
mouse like a paintbrush in a painting program, 2. zooming in on a pixel in 
a map to increase magnification of the area surrounding that pixel.
- Examples of outcomes that can not be expressed in words:  1. the painting 
that results from the use of a painting program,  2. the music that results 
from the use of a recording program (unless it has lyrics - see Checkpoint 
1.2).
- Example of a function that can be expressed in words:  volume control 
knob.  Operated with the mouse the user is required to "turn the knob" by 
clicking and dragging with the mouse.  Operated via a keyboard the user 
tabs to the knob and uses the down arrow key to turn the volume down or up 
arrow to turn the volume up.   The discrete values that are labeled are 
1-11 (1= softest, 11=loudest) [2]
</proposal>

I would prefer to move the examples to the example section of the 
guideline, but wanted to include them here for clarity.

As we discussed last week, there are alternatives that could be provided 
for zooming in on the map. For example, mapquest provides not only the 
ability to select a pixel from the map but also to select  different levels 
of zoom ("zoom level 1" up to "zoom level 10" as well as "zoom in" and 
"zoom out")  as well as directional buttons ("Pan North," "Pan East," 
etc.).  Although the result of mapping a single address does not have a 
text equivalent, Mapquest provides an outcome expressed in words for 
driving directions ("1: Start out going South on 28TH AVE NW toward NW 73RD 
ST. 0.0 miles 2: Turn LEFT onto NW 73RD ST. 0.2 miles" etc.).

Should we modify the success criterion to allow alternatives?
<proposal>
All of the functionality of the content , where the functionality or its 
outcome can be expressed in words, is operable (at least) via a keyboard or 
keyboard interface OR
an alternative to the functionality or outcome that can be expressed in 
words is available.
</proposal>

Thoughts?

[1] <http://lists.w3.org/Archives/Public/w3c-wai-gl/2003OctDec/0588.html>
  This phrase separated functionality that can be accomplished using 
buttons or command line interfaces from functionality such as 
fingerpainting that requires continuous analog control of the 
interface.   Note: often  analog controls are used to operate functionality 
that could be done via the keyboard.  For example - an analog volume 
control could be controlled by tabbing to it and using the up and down 
arrows to 'turn' the knob or 'slide' the slider.  This type of control 
would be covered and should be keyboard controlable. Watercolor painting 
however cannot reasonably be done from the key board in the same way it 
could with a pressure sensitive brush interface.   It would not be required 
under this provision - though a more primitive form of control might be 
provided at a higher level of accessibility and would be beneficial for 
many activities.
[2] <http://imdb.com/title/tt0088258/quotes>  Reference to a scene from 
"Spinal Tap" - a mockumentary about a rock band.
"Nigel Tufnel:  What we do is, if we need that extra push over the cliff, 
you know what we do?
Marty DiBergi: Put it up to eleven.
Nigel Tufnel: Eleven. Exactly. One louder.
Marty DiBergi: Why don't you just make ten louder and make ten be the top 
number and make that a little louder?
Nigel Tufnel: [Pause] These go to eleven. "

-- 
wendy a chisholm
world wide web consortium
web accessibility initiative
http://www.w3.org/WAI/
/--

Received on Monday, 12 January 2004 16:54:49 UTC