Investigated was an inservice training program in elementary school science (grades 1, 2, and 3) designed to increase teachers' achievement of relevant performance skills. Attainment criteria were (1) a change in the teachers' verbal classroom behavior, and (2) an increase in the teachers' scientific knowledge and understanding of science. A pretest-post test control group design was used. The experimental group (17 teachers) participated in the inservice program, whereas the control group (19 teachers) did not. Observations, consisting of tape recordings of four science lessons, were made for each of the 36 teachers prior to the inservice program and were coded into interaction analysis matri;"s. A classroom log was maintained during each lesson. Six months after the summer training program, the observation procedure was repeated. Results indicated that inservice training programs to change teacher verbal classroom behavior are feasible and can be accomplished by local educational agencies at a modest financial level of support. (RS)