Developing functional requesting: acquisition, durability, and generalization of effects.

This study investigated the effects of a language program called the missing-item format, on the acquisition of requesting during snack periods. The missing-item format, an assessment and training approach, develops a child's spontaneous requesting skills in everyday tasks. Generalization and response-durability measures were also collected. The missing-item format produced effects in requests for targeted snack items, but not for the majority of generalization and durability measures. A generalization training program was then implemented, using the missing-item format. As a result, a requesting repertoire that was durable and generalized across multiple settings and stimulus conditions was established in both students.