The aim of this quantitative, causal-comparative study was to examine differences in teachers' perceptions of cooperative learning and factors influencing their implementation in the classroom. In order to assess teacher perceptions and current use of cooperative learning, the Cooperative Learning Implementation Questionnaire (CLIQ) developed by Abrami, Poulsen, and Chambers (1998) was used; it was based on the Expectancy Theory, and evaluated the teacher's expectancy of success, perceived value, and perceived cost. For this study, participants were chosen through a convenience sample. This included third, fourth, and fifth grade teachers in public schools located throughout rural and suburban school districts in Florida and Georgia. The 80 participants included, n = 34 third grade teachers, n = 23 fourth grade teachers, n = 23 fifth grade teachers. A Kruskal-Wallis (H test) was used in this study to determine if a statistically significant difference existed in CLIQ mean scores for: expectancy of success, perceived cost, perceived value, and current teaching practices between the three different groups of teachers. In this study, the results revealed no statistical significant difference, as third, fourth, and fifth grade teachers have similar perceptions of cooperative learning. Additionally, the participants had similar scores for Current Teaching Practices, H(2) = 0.31, p = 0.86, and Teacher Perceptions, H(2) = 0.27, p = 0.87. The study did reveal teachers with prior training in cooperative learning were most likely to implement it. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]