Activity-based intervention and direct instruction: a comparison study.

An alternating treatments design was used to compare the effectiveness of two intervention procedures--direct instruction and activity-based instruction--on the acquisition and generalization of object names by preschool-age children with developmental delays or who were at-risk for such delays. Subjects were given a pretest to determine unknown object names. A systematic alternation of treatments was subsequently provided by trained interventionists. After a baseline period of 1 week, two 15-minute treatment sessions employing activity-based intervention and direct instruction were followed by a 15-minute free-play generalization session, 3 days a week, for 6 weeks. A return to baseline phase was then conducted for 1 week. Structured generalization probes were also administered throughout treatment and 4 weeks after the study ended. Results indicated differential effects for both treatments.