• modelling;
  • question-asking;
  • tokens;
  • retardates

Questioning is an important skill, particularly for retarded children with deficits in accumulated information. Recent strategies for modifying a variety of verbal behaviors have included both token reinforcement systems and modelling procedures. However, the relative effectiveness (i.e., the rate of behavior change) of certain reinforcement procedures, especially with low base-rate behavior (used alone) have recently been questioned. The present study, using an ABAB design, compared the effect of a Token reinforcement system, a Trainer-Model procedure, and a combination of the two procedures on increasing the rate of question-asking. Each condition was in effect for six sessions. Groups of four mildly retarded children (mean age: 10.1 yr) were prompted to ask questions about large photographs, and each of their questions was immediately answered. For the Model group, the Trainer modelled four questions for each subject for each photograph. For the Token group, each question earned the subject a point, which was exchangeable after the session for various items (e.g., candy, ice cream) from a “store”. For the Modelling plus Token group, the procedures were combined. The Model and the Control groups were yoked to receive the same amount of candy as the Token and the Model plus Token groups for behaviors other than question-asking (i.e., being polite). The results indicated that during Baseline conditions, performance across groups was comparable and that the performance of the Control group did not change across time. The Model procedure had only minimal effects on the rate of question-asking, while both the Model plus Token and the Token groups showed significant performance increments. The only significant difference between the Model plus Token and the Token groups was a faster rate of increase early in the first Training condition for the Model plus Token group. This difference, and the low level of performance change for the Model group, was interpreted as suggesting a facilitory effect of modelling procedures on reinforcement contingencies. The discrepancy between previous findings showing relatively minimal changes following reinforcement of low base-rate responses and the present results were discussed in terms of various procedural differences. Educational implications of the present results were also discussed.