English-medium instruction and impact on academic performance: a randomized control study

Stakeholders and researchers in higher education have long debated the consequences of English-medium instruction (EMI); a key assumption of EMI is that student's academic learning through English should be at least as good as learning through their first language (usually the national language). This study addressed the following question: "What is the impact from English-medium instruction on students' academic performance in an online learning environment?" "Academic performance" was measured in two ways: number of correctly answered test questions and through-put/drop-out rate. The study adopted an experimental design involving a large group (n = 2,263) randomized control study in a programming course. Student participants were randomly allocated to an English-medium version of the course (the intervention group) or a Swedish-medium version of the course (the control group). The findings were that students enrolled on the English-medium version of the course answered statistically significantly fewer test questions correctly; the EMI students also dropped out from the course to a statistically significantly higher degree compared to students enrolled on the Swedish version of the course. The conclusion of this study is thus that EMI may, under certain circumstances, have negative consequences for students' academic performance.