This News.com article (http://news.com.com/2100-1032_3-1022814.html)
discussed a problem with using visual Turing tests - the blind cannot use it.
---snip---
Efforts to create tests aimed at distinguishing humans from machines go
back decades, with the most famous formulation of the problem posed in 1950
by the English mathematician and World War II "Enigma" code breaker Alan
Turing. Turing's controversial hypothesis was that a machine could be
defined as "intelligent" if a questioner could be fooled into believing it
was a person.
Visual tests in a sense turn that theory on its head, assuming that a
machine is defined by its inability to perform a task that is easy for most
humans to accomplish.
The increasingly popular visual test, and the difficulty of using current
work-arounds, has raised enough hackles among advocates for the disabled
that working groups within the World Wide Web Consortium's (W3C) Web
Accessibility Initiative have begun discussions on how to standardize an
alternative.
Two WAI working groups are hashing out proposals to guide Web sites in
designing blind-friendly bot repellants, and the WAI hopes to address the
issue in the next working draft of its Web Accessibility Guidelines,
Version 2.0, which is due by year's end. So far, published working drafts
of the guidelines are silent on the issue.
----snip----
As Vernon pointed out previously we do not know for sure if these tests
cannot be passed by a machine. Also, nothing can stop spammers from hiring
real people to do the task. The financial difference would be negligible.
This raises the issue of whether the tests are needed in the first place.
C/R systems also fall under this issue.
It would be worthwhile to contact the W3C in order to keep abreast of any
standards they make in the area.
Yakov
_______________________________________________
Asrg mailing list
Asrg(_at_)ietf(_dot_)org
https://www1.ietf.org/mailman/listinfo/asrg