Krisztián Józsa and Györgyi Székely: Creating a Cooperative learning Environment in MAthematics Education This empirical study compares the effectiveness of a cooperative and a teacherdominated learning environment in a design including an experimental and a control group of ninth grade students in the academic stream of secondary education. 83 students in the experimental group participated in cooperative learning activities and 81 students in the control group received teacherdominated instruction. Both the experimental and the control groups were divided into five learning groups each. The experiment covered twelve consecutive math lessons on word problems. Pre and posttests were administered. The results show that, as regards development in problem solving skills related to word problems, cooperative learning was more effective (effect size: .49). Furthermore, the skills of cooperation developed significantly for students studying in a cooperative learning environment and their math attitudes also improved. However, this environment did not have significant influences on students’ math selfconcept, mastery motivation and competitive aspirations. Students and teachers agreed in finding a better classroom climate during cooperative learning sessions than in teacherdominated settings and both were more motivated for accomplishing their tasks under the former condition. Still, the experiment revealed that an exclusive environment of cooperative learning is not suitable. Some teachers and students alike found twelve such consecutive lessons overbearing. It appears that cooperative learning periods could be most effective dispersed over the academic year, varied with other learning environments. MAGYAR PEDAGÓGIA 104. Number 3. 339362. (2004) Levelezési cím / Address for correspondence: Józsa Krisztián, SZTE Neveléstudományi Tanszék, H–6722 Szeged, Petőfi S. sgt. 30–34. Székely Györgyi, Illyés Gyula Gimnázium, H–2040 Budaörs, Szabadság u. 162. 
