The Information Processi ng Approach to Cogn ition Stephen E. Palmer University of California, Berkeley Ruth Kimchi University of California, San Diego Of the many alternative approaches available for understanding cognition, the one that has dominated psychological investigation for the last decade or two is information processing (IP). For better or worse, the IP approach has had an enormous impact on modern cognitive research, leaving its distinctive imprint on both the kinds of theories that have been proposed and the kinds of experiments that have been performed to test them. Its influence has been so pervasive, in fact, that some writers have argued that IP has achieved the exalted status of a "Kuhnian paradigm" for cognitive psychology (Lachman, Lachman, & Butter- field, 1979). It is unclear whether or not this claim is really justified, but the fact that it has even been suggested documents the preeminence of IP in modern cognitive psychology. Whenever an approach so dominates a scientific field, it is important to understand-or at least to try to understand- its foundations: the nature of the assumptions that underlie its use. These must be scrutinized for their consisten- cy, plausibility, empirical support, utility, and potential limitations. Only then can one begin to see how the approach is related to others, how firmly it is rooted, why it has taken the field to its present state, and where it is likely to lead in the future. The goal of such an enterprise is essentially to provide a theory of a particular scientific approach to capture the activities and intuitions of its practi- tioners accurately and succinctly. If the practitioners agree that the analysis succeeds in capturing the nature of their beliefs and their work, it can eventually replace vague intuitions with well-defined constructs as the basis for further research . We believe that the time has come to examine the foundations of information processing in psychology. There has been some work along these lines, but it has