Abstract

• This study aims to investigate the impact of direct instruction in teaching mathematics at the middle school level. Two Branch Basic Education High Schools: BEHS (Branch), Tesu and BEHS (Branch), Ywar Thit were selected by using simple random sampling method. One of the Quasiexperimental designs, viz, the Nonequivalent control group design was used in this study. The numbers of participants in this study were (168) Grade Nine students. Two intact groups in each school were randomly assigned to experimental group and control group. Before the treatment, all the selected sample students were administered a pretest to know whether the groups had the same background knowledge in mathematics. There was no significant difference between the groups on the pretest. During the treatment period, the experimental groups were taught by using direct instruction while the control groups were taught by using formal instruction. The same contents were given for three weeks in both selected schools during the treatment period. After the treatment, both groups were administered a posttest. The data was analyzed by using independent samples t test. Based on the research findings of the posttest scores, the achievement of the groups who were taught by using direct instruction were significantly higher than that of the groups who were taught by using formal instruction. So, direct instruction was more effective in improving the students’ achievement. Moreover, the students became more active and interested in teaching learning process by using direct instruction. Thus, mathematics teachers should be encouraged to use direct instruction in teaching mathematics at the middle school level.