While i would never have thought of the answer myself the answer is pretty easy. You need to make the problem more difficult. Text recognition simply is not a hard enough problem.
What is hard for computers and easy for humans? Simple. Asthetics and object recognition.
For example: http://ieeexplore.ieee.org/Xplore/login.jsp?url=/iel5/10670/33674/016022...
Ive heard of the same thing but with different questions like:
(with 4 animal pictures numbered 1-4) put them in order dog,cat, mouse,horse
(with many human pictures) which of the several pictures is a woman
which person is ugly
etc....
captchas
While i would never have thought of the answer myself the answer is pretty easy. You need to make the problem more difficult. Text recognition simply is not a hard enough problem.
What is hard for computers and easy for humans? Simple. Asthetics and object recognition.
For example:
http://ieeexplore.ieee.org/Xplore/login.jsp?url=/iel5/10670/33674/016022...
Ive heard of the same thing but with different questions like:
(with 4 animal pictures numbered 1-4) put them in order dog,cat, mouse,horse
(with many human pictures) which of the several pictures is a woman
which person is ugly
etc....
hope it helps