The Effect of the Medium of Instruction Language on the Academic Success of University Students

The aim of this study is to investigate the effects of instruction in a students' non-native language on the academic success of university students. To analyze the effect of medium of instruction language on student success, we utilized the data from a Turkish university. The university has many departments which offer two types of BA/BS degree programs: in one program medium of instruction is English in the other one it is Turkish. All other aspects of the programs are identical and students have very similar academic and socioeconomic backgrounds in both degree programs. Our analysis indicates that instruction in the non-native language of students affect the academic success of students negatively. This negative influence is higher in the first year of the university but still exists in the fourth year. However we found the opposite effect for the students with merit based scholarships that are usually brighter and more motivated. We should also note that we are not measuring the benefits of English-medium instruction. Thus our results do not automatically imply that, English-medium instruction is harmful to the students