Channels and stages in human information processing: A limited analysis of theory and methodology (Q1059020)

This article reviews the status of the theoretical construct of capacity. Four basic questions are discussed: (1) What is capacity? (2) How is capacity measured? (3) Is capacity limited? (4) If so, where is it limited? It is claimed that empirical answers to these questions have been unsatisfactory due to theoretical and methodological issues that need be resolved. Data are presented to illustrate such difficulties. The construct of capacity has become more and more vacuous and caution is required whenever capacity is invoked to explain behavior. These problems can be overcome by careful research and well-defined models. Capacity can be a soup stone, a millstone, or a touchstone, depending upon how it is used.