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Re: word verification

for

From: Jukka K. Korpela
Date: Feb 9, 2006 11:45AM

On Thu, 9 Feb 2006, Kynn Bartlett wrote:

> CAPTCHA is almost always user hostile at the expense of convenience
> for the developer and/or site user.

Indeed. The same applies to E-mail address munging.

> Hostile to ALL users. We just notice the hostility more blatantly when
> users with specific needs are shut out.

The most common captchas discriminate against the blind, the visually
impaired, and people with difficulties in seeing patters of characters in
a messy setting (hey, that's me!). Suggesting an alternate route to such
people means telling they're secondary people, and I wouldn't be surprise
if the quality of the service corresponded to this.

The captchas that are meant to overcome such difficulties, by asking
"simple" questions, discriminate against people with cognitive
difficulties, or with limited knowledge - about the specific subject aream
which might be something US-centered or otherwise culturally exclusive.

Briefly, anything that is difficult enough to keep advanced robots away
will keep potentially millions or billions of people away.

Yet, the problem remains, even if we recognize that most proposed
solutions create worse problems that they purport to solve. Anything on
the web can be used, one way or another, by any person, or any dog, or any
robot. How do we filter out the data coming from robots (and from dogs,
and from people who behave worse than dogs)?

This is quite a puzzle. But any solution that requires the user to prove
he is human by his ability to see or to know things or to do things is
bound to discriminate against many people. There is no _single_ external
activity that is necessary and sufficient to classify a being as human.

--
Jukka "Yucca" Korpela, http://www.cs.tut.fi/~jkorpela/