Abstract

• The purpose of this study was to investigate the effectiveness of Inquiry Training Model in teaching mathematics at the basic education middle school level. The experimental study was used to compare the mathematics achievements of the students. Two basic education high schools were randomly selected from Singu Township in Mandalay Division. The subjects were (219) Grade Eight students from two schools; BEHS (Singu) and BEHS (Let Pan Hla). The design used was the pretest-posttest non-equivalent control group design, one of the quasi-experimental designs. The instruments used in this study were pretest, lesson plans, and posttest. The two groups from each school were randomly divided into experimental and control groups. Each group was pretested before the treatment. The results showed that both groups were equal. And then, the students in the experimental group were taught by Inquiry Training Model while those in the control group were taught by the conventional method of teaching. After four weeks’ treatment, a posttest was administered to each group. Analysis of covariance (ANCOVA) was used to analyze the data. The findings showed that there was a significant difference between the experimental and control groups in BEHS Singu (F (1,97) = 13.134, p < .001) and in BEHS Let Pan Hla (F (1,118) = 24.786, p < .001) on the posttest achievement. Therefore, research findings showed that Inquiry Training Model had a positive effect on developing the students’ mathematics achievement at the middle school level.