Articulation therapy was administered to 240 children by 17 speech clinicians working in a suburban school system. Articulation testing was completed both before and after an eight and one-half months' treatment period. Group therapy was found to be as effective as individual therapy, regardless of the severity of speech defectiveness or grade levels of the children.

Articulation therapy was administered by 20 speech clinicians to 288 children in a suburban school system. Articulation testing was completed both before and after an eight-and-a-half month treatment period. Therapy was found effective for all groups regardless of grade level or severity. However, subjects with poor stimulability scores derived significantly more benefits from therapy than did those having good stimulability scores. Stimulability performances were related to articulation improvements in untreated groups at certain grade levels. Compared with subjects having milder degrees of defectiveness, subjects with more severe problems improved more in kindergarten than at the second grade level.

Articulation therapy was administered to 120 retarded subjects. Subjects were examined on two articulation tasks. One task was a version of the Carter/Buck Prognostic Speech Test, and the other a picture version of McDonald’s deep test of articulation. Subjects with both poor and good prognostic scores and moderate and severe degrees of articulatory defectiveness were selected. They were randomly assigned to (a) a control group of subjects receiving no speech therapy, (b) an experimental group of 60 subjects receiving one period of group articulation therapy weekly, or (c) an experimental group of 60 subjects receiving four periods of group articulation therapy weekly. Group articulation therapy was administered by four clinicians in a school setting. Subjects who received group articulation therapy four times per week during the experimental period significantly improved their articulation as measured on a picture deep test when compared with control group subjects. Subjects receiving group articulation therapy once weekly during the experimental period were not significantly improved compared with control group subjects. Significant differences between groups were not found on an imitative sentence articulation test.