Generalization of the Monterey Behavioral Sciences Institute operant language program was assessed. Six male and three female children (4 years, 4 months to 6 years, 3 months) receiving language remediation were randomly assigned to (I) the Monterey program for the syntactic structure "is interrogative" (including the home carryover phase) plus an extended transfer program devised by the investigators (II) the Monterey "is interrogative" program alone (including the home carryover), or (III) a control activity (articulation training). Language samples evoked by a variety of language tasks were collected outside the treatment settling preceding and following treatment. Standard within-clinic measures indicated that groups I and II improved a significant, equal amount. However, the extraclinic language measures showed that group I demonstrated significantly greater improvement than group II; neither group II nor group III showed significant extraclinic improvement. Extraclinic generalization occurred, therefore, only for the group receiving the special extended transfer training.