Repeated acquisition in the analysis of rule-governed behavior.

Five children, ranging in age from 3(1/2) years to 5(1/2) years, were taught various four-response chains using conditioned reinforcement. Experiment 1 investigated the effects of presenting "instruction" stimuli-a sequence of lights over the correct response buttons-to assess their role in facilitating the acquisition of a chain of responses. Without the "instruction" stimuli, children made many errors before responses were brought under the control of the programmed contingencies. When confronted with the same contingencies later in the day, these subjects made fewer errors. In contrast, in the presence of the "instruction" stimuli, subjects made virtually no errors. However, when the "instruction" stimuli were discontinued in the subsequent session, all 5 subjects made errors. In Experiment 2, the subjects were taught to verbalize the contingencies during the phase without the "instruction" stimuli. This resulted in errorless performance during the subsequent exposure to the same procedure, but errors nevertheless occurred again during reexposure to the procedure with the "instruction" stimuli discontinued.