Date of Award


Degree Name

Doctor of Philosophy



First Advisor

Dr. James E. Carr

Second Advisor

Dr. John Esch

Third Advisor

Dr. Linda LeBlanc

Fourth Advisor

Dr. Jack Michael


Verbal Behavior programs for children diagnosed with autism typically teach novel language in the context of multiple verbal operant arrangements. Commonly called "mixed verbal behavior", this involves the interspersal of various exemplars across verbal operant categories. Despite the current recommended use of this teaching procedure, only 2 studies to date have empirically evaluated its effectiveness (i.e., Arntzen & Almas, 2001; Carroll & Hesse, 1987). In both of these studies, mixed mand-tact training resulted in faster mean acquisition of tacts than tact-only training. In Experiment 1 of the current investigation, a systematic replication of previous studies was conducted with 3 typically-developing children. Although tacts were acquired in fewer mean sessions during the multiple verbaloperant condition than in the single-verbal operant condition across all participants, mean differences were negligible andthe effect was inconsistent across stimulus sets. In Experiment 2, a direct replication of Carroll and Hesse was conducted with 2 typically developing children. Mand-tact training did not produce more rapid acquisition of tacts for participants. The results are discussed in the context of idiosyncratic differences between current and previous procedures, and the value of further research on this potentially valid but elusive phenomenon.

Access Setting

Dissertation-Open Access