Abstract

• The major purpose of this study is to investigate the effects of cooperative learning on students' achievement in grade nine economics. This study was conducted using quantitative research method. Quantitatively, an experimental study was used to compare the students' economics achievement between the control group and the experimental group. The posttest only control group design was used in this study. In this experimental study, the subjects were Grade Nine students (economics combination) who were selected and tested from two schools; No. (1) Basic Education High School, Mayangone and No.(4) Basic Education High School, Insein from Yangon Region. The subjects, (64) Grade Nine student were chosen from each school. The students from each school were randomly divided into two groups: experimental group and control group. The subjects from the experimental group were taught by using cooperative learning method and those from the control group were taught by using formal instruction. After that, a posttest was administered to two groups. Independent samples t-test was used to analyze whether there were significant differences between two groups. The results showed that the students who received a treatment by using cooperative learning method were significantly higher than those who received formal instruction. Examination of the mean and t-test at No. (1) Basic Education High School, Mayangone was (t = 6.26, df = 62, MD = 3.00, p < .001) and No. (4) Basic Education High School, Insein was (t = 5.08, df = 62, MD = 2.56, p < .001). The result indicated that there was a significant difference between the two groups. Therefore, research findings proved that cooperative learning method has positive contribution to the economics teaching and learning at the high school level.