Ravens exampleLooking at the matrix to the left, what image completes the pattern? 

This is a matrix reasoning puzzle. These puzzles tap into basic facets of human intelligence: the ability reason abstractly—to see meaning in complexity, complete patterns, and solve novel problems.

Our project is crowdsourcing the design of a set of matrix reasoning puzzles. This is a competition, so winners will receive cash prizes and co-authorship of a scientific paper. >>

UPDATE: The winners of the best puzzles and the most submissions have been announced. Congratulations!
UPDATE: We are offering the contributors who had items rejected to submit revised versions (you will receive an email if this applies to you). We will award an additional prize of $200 to a random contributor that submits a revised (and now valid) item.