Joking aside, a non-geeky take on the need for programatic determinism

Necessary features for accessible 
perception:

The primary usage mode for authoring 
tools should support all of the 
properties below.  Moreover, it should 
trigger an error if the user violates 
one of these rules in a way the 
authoring tool can detect. This is not 
always possible.  For example, text 
hidden in bitmap data cannot be 
distinguished with 100% accuracy by 
any program, but a lack of supporting 
alternative text can be.  So, if an 
authoring tool encounters an 
undocumented image it should give a 
message like, "The image does not have 
an alternative text description. If 
the image contains digitized text for 
reading then the text description 
should contain all of the digitized 
text."

1.  All text should be saved in a form 
that can be recognized by a machine 
with 100% accuracy.

2. All formatting that is used to as 
part of the logical organization of a 
document such as: headings, lists or 
tables of data, can be recognizable by 
a machine with 100% accuracy.

3.  All non-textual data should given 
meaningful alternative text 
descriptors that can be recognized by 
a machine with 100% accuracy.

In summary: data that is text, data 
that organizes documents, and data 
that clarifies the context and meaning 
of images and sounds should be 
readable by machine with perfect 
accuracy.

If an authoring tool does not 
encourage these features in it primary 
output for its primary authoring 
community, then it encourages 
inaccessible technology.

This all comes basically from ATAG 2.0 
Checkpoint A.1.5.

Wayne

Received on Sunday, 9 July 2006 01:28:15 UTC