This study was conducted in 1989 in a suburban school district in Oregon for the purpose of determining the impact of high, medium, and low usage levels of cooperative learning on teacher efficacy. Elementary school teachers in the district were engaged in a staff development training program for teaching cooperative learning in the classroom. This type of learning includes helping, communicating, encouraging, teaming and supporting, with the teacher acting as model. Elementary classroom teachers (N=129, a 71% response rate) responded to a questionnaire which gathered information about an independent variable, the amount of classroom time spent in cooperative learning situations within a week's time, and its effects on teacher efficacy. Results indicated that teachers using the highest level of cooperative learning experienced the highest levels of efficacy, power, confidence in working with students, and willingness to innovate. Since this study is exploratory, suggestions are made for further investigation through experimental designs. The survey form is appended. (LL)