Suppose some Intelligent Algorithm can learn to play tic-tac-toe. Tic-tac-toe is such a simple game that it can be exhaustively learned via memorization – but this is not what I mean here. I mean that the intelligent algorithm (IA) actually has the ability to generally learn, and that it has used this ability to learn tic-tac-toe. What would one like the IA to now know? Well, in addition to knowing the rules and optimal strategy of the game, the IA should also have figured out that tic-tac-toe is played on a planar grid, and that the winning positions correspond to horizontal, vertical, and diagonal lines on this grid.
Now after it has learned 3 x 3 tic-tac-toe, suppose that we want our IA to also learn to play 4 x 4 tic-tac-toe (perhaps this game should be called tic-toc-toe-tum). The IA should be able to use what it has learned in the 3 x 3 game to more easily learn the 4 x 4 game, and it should explicitly “understand” this relationship. Concretely, what does this mean?
I believe this is one of the couple fundamental open problems in machine learning.