摘要：This study investigated the effect of working in homogeneous and heterogeneous pairs on students’ writing skill using quasi experimental research design involving 40 students. The first group consisted of 20 homogeneous pairs (paired with similar pre-test scores) while the second group consisted of 20 heterogeneous pairs (participants with high scores are paired with those having low pretest score). Then they were assigned to work on their pairs to write descriptive essays three times. After that they were assigned to write descriptive essays individually. The data was analyzed using independent sample t test to compare the students’ post-test scores. The result shows that after the experiment the quality of descriptive essays produced individually by the students from heterogeneous group was on the average significantly better than the quality of descriptive essays produced by the students from the homogeneous group. Further investigation on comparing the quality of descriptive essays produced individually by the high achievers from heterogeneous group and high achievers from homogenous group shows that the quality was not significantly different. While the quality of descriptive essays produced individually by low achievers from heterogeneous group is significantly better that the quality of descriptive essays produced individually by low achievers from homogenous group. It means that the heterogeneous grouping was more effective than the homogeneous grouping only for low achievers but not for high achievers. Furthermore, the questionnaire result found that the participants in heterogeneous group had more positive attitude toward the collaborative work than those in homogeneous group.
