Connecting the Dots: Impact of CLIL on Vocabulary Size and Content Mastery in Higher Education

This study aimed at investigating the impact of Content and Language Integrated Learning (CLIL) on higher education students’ vocabulary size and content mastery. The study involved a sample of 58 students from Middle East College in Omanduring the academic year 2019-2020. The experimental group consisted of 28 students, while the control group consisted of 30 students. The research instruments included a vocabulary size test and a content mastery test. The results of this study revealed that there was no statistically significant difference between the control and the experimental groups’ scores in the vocabulary post-test and the delayed-test. However, the vocabulary learning gain of the experimental group was higher than that of the control group, which means that CLIL had a positive impact on students’ vocabulary size, but this impact was not statistically significant. Moreover, there were differences between the control and the experimental groups’ scores in the content mastery test in favor of the experimental group. However, they were not statistically significant