In this paper the theory that human thinking proceeds according to the computer model, or symbol manipulation, is reviewed and challenged. The research used as subjects five highly rated tournament chess players who "thought aloud" during a chess game to provide tape recorded protocols of decisions made while playing. These protocols were then analyzed phenomenologically in three steps. Results are presented for nine specific issues in which the phenomenological approach differs from computer simulation programs: the look ahead function, purposiveness, goal seeking, memory, overall sense of the task, level of knowing, role of experience, expectations, and opponent's style. The most significant general divergence between the two methods is noted as the computer's ability to thematize millions of possible subsequent combinations of moves while a person can thematize only a few dozen possibilities. The paper concludes that, given the divergence between the two models, a descriptive method can be useful for the psychology of thinking. Results are followed by a list of references. (ABB)