Reducing Responding of Retarded Persons by Dro Schedules Following a History of Low-Rate Responding: A Comparison of Ascending Interval Sizes

Abstract

In order to assess the reductive effects of stimuli associated with different initial DRO values in a program with increasing DRO intervals, a two-phase experiment was conducted in a laboratory setting. In the first phase, subjects responded under a four-ply DRL multiple schedule. In the second phase, they responded under a different multiple schedule [mult (DRO₁) (DRO₂) (DRO₃) (DRL)] in which the initial values of the three Dro components were 1, 12, and 20 sec. Upon criterion responding, values were increased along a series of 1, 2, 6, 12, 20, 30, 42, 56, and 72 sec.

Results of Phase 2 indicated that (a) there were fewer total responses in the DRO₁ component than in the other components for all subjects, and fewer responses in the DRO₂ than in the DRO₃ component for two subjects; (b) the reductive effects of the Dro components transferred to the Drl component; (c) response rates tended to increase initially when the Dro interval was increased for a component; (d) the order of efficiency in establishing schedule control was DRO₁ DRO₂-DRO₃; and (e) a prior history on Dro schedules with small values may have resulted in reduced responding under Dro schedules with higher values. Results were, discussed in terms of factors which can affect the success of Dro schedules in reducing responding.