Assessing the effects of CLIL on Korean high school students’ writing

This study examines the effects of content and language integrated learning (CLIL) on several aspects of the written language competence of learners of English as a foreign language (EFL). Controlling for L2 proficiency and L1, the study compares the English written narratives produced by CLIL (N = 29) and non-CLIL (N = 35) 11th-grade students in terms of syntactic complexity, lexical complexity, cohesion, and writing quality. The results show that the CLIL group outperformed the non-CLIL group according to measures of mean length of clause, lexical sophistication, lexical diversity, and writing quality, while the non-CLIL group’s writing showed greater semantic cohesion. The findings contribute to CLIL research, previously limited to a focus on morphosyntactic features or writing quality, by expanding it to investigate CLIL effects on syntactic complexity, lexical complexity, and cohesion in addition to writing quality.