Thinking formation of a new mental representation, created through transformation of info you may already have by complex interaction of mental attributes of judging, abstracting, reasoning, imagination, and problem solving. Problem solving thinking directed toward handling a certain situation involving the formation of responses and the selection among possible responses. What is a problem: there is an initial state, there is a goal state differing from the initial state, and then the process of going from the initial to the goal state isn"t completely obvious. Four features of problems: goal description of what constitutes a solution, description of objects relevant to achieving a solution, a set of operations toward the solution, a set of constraints not to be violated. Herb simon: studied protocols of subjects talking during problem solving. Form initial problem representation try to plan potential solution problem) (if fail and can"t formulate solution try to reformulate.