Temporal patterns of key pecking by pigeons were shaped by a schedule in which the delivery of food was contingent upon a measure of the overall extent to which the temporal pattern of behavior within a 5-sec trial conformed to a required pattern. This pattern approximated a constant rate of change in the rate of key pecking throughout the 5-sec trial. In comparison with behavior maintained by a classical fixed-interval 5-sec schedule, the new schedule controlled a better approximation to a "scallop" within individual trials and greatly reduced intersubject variability. These results are consistent with the view that the delivery of a reinforcer after a behavioral pattern a few seconds in duration may strengthen the entire pattern as a unit, or operant. The response topography contiguous with reinforcement may be a negligible fraction of the strengthened operant. One implication of this view is that mean response rate for such brief responses as key pecks and lever presses is a byproduct of whatever patterns are strengthened, and generally will not reveal fundamental controlling relationships, whenever a reinforcer is not contiguous with all the behavior on which it is contingent.
