On Fri, 10 Dec 2004 14:20:10 +1300 (NZDT), Richard A. O'Keefe
<ok at cs.otago.ac.nz> wrote:
> John Pierce <john.raymond.pierce at gmail.com> wrote:
>         For instance, as part of the submit process you make your edits to the
>         swiki, type the letters you see in the image below in the text box
>         
>         @@@   @   @   @   @@@
>         @    @  @@@   @   @   @
>         @@@   @   @   @   @@@
> 
> The problem with this is that while I can guess that the first letter is
> "C" and that the last two are "I" and "D", I have no idea what the stuff
> in the middle is.  My eyesight is up to the task of seeing every single
> "@" sign, but if this were real, you'd have just locked me out for no good
> reason.

Yeah -- the @ sign was not the best choice -- the technique was all I
was presenting.  Most captcha's use a gif image instead of ASCII art,
I just though ASCII art could be used as a cheap alternative.  By the
way, the captcha I put above is "OHIO".  I guess what I presented
above was rather a captcho (completely automated public Turing test to
keep computers and humans *out*).

> A far more reasonable challenge-response hack for a Squeak wiki would be
> to name a method and a line number and ask someone to type the words they
> see in that line.

One thing that I think that could be explored as a possible captcha
implementation is the solving of a math problem that probably turns
out to be quite hard to implement without special support (a large
number implementation for instance).  For instance, how about the
following captcha:

Please enter three hundred and eight five factorial:  

The user would, of course, just do this in a workspace and easily put
back in the text box:

77789258200022682857262524611415309149847055830033034109882689650252194969679085094625004160614777142840032749700960018016880257150600760973387063625465151973977979879777238796637512249859636989563488396079390053459321567631753747632959254354510911723355274009752250302167318747380739790814322278867448117858757749562590484682648929702787022262746051020728642181787640182285101009794037643386965050892754788419216225960187559786147684262118679388088477835523732297315903458517415743852458900263831761206810157984267061814227152746582087453048037976549155699326580418348947419613236026536061943703203702535568264627840497844830538486783779191495261331727855882465027081574803712043311976266948667916187775974266352925870275040925817241600000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000

Probably not the easiest answer for most systems since it exceeds a
large int and Squeak users could easily answer it.  This could be a
bit to manage though (in size) and may be quite unfriendly.

Lastly, while I think that is interesting to try to find a puzzler
that is easy to answer in Squeak, we could keep the captcha far
simpler with the probably the same results.

For instance, make the captcha be a very simple reading comprehension
problem or painfully simple trivia, like the following:

Jim and Suzy are the children of Jack and Betty.  Suzy is what to Jim?
What do we call water when it freezes?
Richard Alan Butler's middle name is?
Dallas, TX is the capital of what state?
Please tell me what 1 plus 3 minus 2 equals (enter as a numeric)?

Of course, you'd have to have hundreds of trivial trivia problems, but
I could contribute 30 or 40 in short order.

Regards,

John

-- 
If at first the idea is not absurd, then there is no hope for it. --
Albert Einstein