Evaluating the treatment effect of repeated probes.

This study investigated the effect of the administration of frequent and infrequent probe lists on generalization to novel stimuli. Four subjects with multiple functional articulation errors were taught to produce two different sounds, and generalization was measured on three probe lists. Two of the probe lists (one for each sound) were administered infrequently, and the third probe list (for one sound) was presented at each treatment session. The results indicated that the frequent rate of administration of probe lists did not produce any predictable effect on the extent of generalization or the occurrence of a practice effect. In general, the data continue to support the use of probe lists as an effective tool to measure generalization.