The impact of adjunct instruction on EFL academic writing at university

Adjunct instruction (AI), a form of content-based instruction, can provide students with opportunities to learn disciplinary discourse in context. Few studies have explored the extent to which AI affects students’ written production over time. This study aims to analyze the impact of a 60-hour AI course in English on writing complexity, accuracy, fluency (CAF) and on holistic measures in two groups with different exposure to English. The participants were 51 first-year Dentistry students from two strands, English-Medium of Instruction (EMI) (n = 21) and first language (L1 Catalan/Spanish) (n = 30). After 60 hours of AI, the EMI+AI group improved lexical diversity, while the L1+AI group improved accuracy and some holistic measures. Correlations between CAF and holistic measures indicate defining features of second language writing in each strand. The benefits of adjunct instruction for writing development are discussed in the light of the two settings explored.