On the impact of extramural English and CLIL on productive vocabulary

Abstract: In this thesis, the possible impact of English encountered and used in two different contexts – in content and language integrated learning (CLIL) and through extramural English (EE) – on students’ writing proficiency is investigated. More specifically, students’ vocabulary use when writing different text types is explored; in particular, attention is drawn to progress in productive academic vocabulary. Three empirical studies were conducted: a cross-sectional study involving 37 students in grade 9 (aged 15–16), and two longitudinal studies, involving 230 students (146 CLIL/84 non-CLIL) in upper secondary school in Sweden. The nature and frequency of students’ use of EE were investigated using two different surveys. Students’ texts, covering different registers, were analysed, mainly by corpus-based methods. In the cross sectional study, the focus of text analyses was on register variation, whereas students’ use of academic vocabulary was analysed in the longitudinal studies. Findings suggest that effects of EE may be greater at lower proficiency levels than at higher. The results also indicated that register variation was greater among those students in grade 9 who frequently used English in their spare time than among those with infrequent exposure to EE. At upper secondary level, the frequency of EE correlated with productive academic vocabulary only in the first year; for progress over time, high exposure to EE did not predict a more positive development. CLIL students used academic vocabulary to a larger extent than non-CLIL students already when they started their CLIL education, but they did not progress more; the gap between CLIL and non-CLIL students did not widen over three years.