A Study on the Effectiveness of Differentiated Instructional Approach in Promoting English Grammar Learning Achievement on High School EFL Students, Addis Ababa, Ethiopia

Differentiated instruction hasn’t been commonly practiced in Ethiopian EFL class and its effectiveness on struggling, grade level and advanced students hasn’t been empirically evidenced on high school students English grammar learning achievement. Consequently, this study investigated effectiveness of differentiated instruction on the struggling, grade level, and advanced students’ English grammar learning achievement. The study adopted the quasi-experimental design. A total of 47 grade twelve students (EG: 23 and CG: 24) were randomly selected and pretested to confirm comparability by using English grammar learning achievement test. The experimental group was exposed to differentiated instruction for ten weeks while the comparison group experienced the one-size-fits-all approach. The pre-test and post-test quantitative data were analyzed using SPSS version 25 software. The t-test inferential statistical data analysis results showed the struggling, grade level and advanced students significantly outperformed, but no significant change was noticed for male and female students. The study concluded that differentiated instruction tremendously  enhanced students’ learning achievement.    