The fixed-interval scallop in human affairs.

"Fixed-interval scalloping" is used to describe certain everyday patterns of behavior in textbooks and other educational communications. This is a misleading use of the term. It implies that the behavior is accounted for by the schedule, when, in fact, many other variables are operating. This paper reviews eleven such variables and the research evidence on them. These variables provide a more adequate account of complex behavior and point up areas of limited knowledge requiring further research in both laboratory and applied settings. Extrapolating from basic research on human fixed-performance suggests that there are phenomena of mutual interest to both basic and applied behavior analysts.