definition of "input error" - my action item

Hi,

Per my action item from last Thursday's Team C teleconference relating to 
the meaning of "input error", I located the following references:

(a) definition of "input" - whatever goes into the computer (noun), or the 
act of entering data into a computer (verb) [1]
(b) definitions of "error" on the Web (relating to "incorrectness" [2]
(c) definitions of "error" as "departing from the truth difference between 
observed
value and true value" [3]
(d) definition of "computer_error" as "an occurrence of an incorrect result 
produced by a computer" [4]


Considering the definitions provided in these resources, in the context of 
Guideline 2.5 [5] and testability, would the essence of the definition be 
"any observable (measurable?) incorrectness relating to entering of data 
into a computer"?   "Incorrectness" would then be "a deviation of an 
observed value from a reference or truth value"?    Using this approach 
might mean that "incorrectness" could be tested..

How restrictive or expansive do we want the definition of "input error" to 
be? Also, "error" is used alone in other places in Guideline 2.5, so the 
definition of "input error" should probably be consistent with a definition 
of "error" alone in Guideline 2.5.   Do we want to talk about the act of 
entering data into a computer, or whatever goes into a computer (the former 
may have a time component and discusses data only, whereas the latter is 
not so restrictive)..

Thoughts? Comments?
Thanks and best wishes

Tim Boland NIST

[1]: http://www.webopedia.com/TERM/i/input.html
[2]: http://www.google.com/search?hl=en&lr=&oi=defmore&q=define:error
[3]: http://www.brainydictionary.com/words/er/error161402.html
[4]: http://www.wordreference.com/definition/computer_error
[5]: http://www.w3.org/TR/WCAG20/#minimize-error