---------- Marcel Popescu[SMTP:mdpopescu@geocities.com] wrote: An interesting idea has surfaced on the freenet-chat list: is it possible to build a program that creates some sort of a puzzle, whose answer the generating computer knows (and can verify), but which can only be answered by a human being, not by a computer? [Additional requirement: it should be easy for the human to answer the puzzle.]
My proposal was to randomly create an image, which should be 1) easily recognizable by a human (say the image of a pet), but 2) complex enough so that no known algorithm could "reverse-engineer" this. [You need a randomly-generated image because otherwise one could build a large database of all the possible images and the correct answers.] Background information would also be very useful - see http://www.digitalblasphemy.com/userg/images/969403123.shtml - it's easy for a human being to identify the animal in the picture, but (AFAIK) impossible to write a program to do the same thing.
Ideas?
Mark
That's a really interesting question. My off-the-cuff answer would be 'no'. The constraints which say that the problem is randomly generated by a computer and the answer also evaluated by a computer are the killers. Any problem which one computer can create, and solve, can also be solved by another. Perhaps one could generate the solution, and find a problem which is solved by that solution, but finding a type of problem which humans will always solve one way, and computers another is the rub. You refer the the problem of recognizing a photo of an animal. It used to be said that no computer program could reliably distinguish between a dog and a cat, but I'm not sure that's the case since the development of neural networks. Almost any question which has a solution which is clear, unambiguous, and easy determined by a human can probably also be solved by either a regular program or a neural net. What you are really attempting to find is a reliable, fast, single-question Turing test. I'm far from sure this is possible. Peter Trei