Formulaic sequences and EAP writing development: Lexical bundles in the TOEFL iBT writing section

•We investigated lexical bundle use in written TOEFL iBT responses.•Lexical bundle frequency decreased as proficiency level increased.•Bundle functions and fixedness remained constant across proficiency levels.•TOEFL iBT bundle usage differed from that in both student and published writing.

Formulaic sequences are widely used in academic writing and are known to be an important aspect of EAP writing development. However, little research has investigated the frequency, function and degree of fixedness of their use by ESL writers across proficiency levels. This study examines the use of lexical bundles in written responses across three proficiency levels in the TOEFL iBT (N = 480). Bundles that were identical to those found in the prompts were analyzed separately. Biber, Conrad, and Cortes' (2004) taxonomy was used to identify bundle functions. Following Biber (2009), the degree of fixedness for each of the four slots in the bundle was investigated in relation to the other three. The results indicate that lower level learners used more bundles overall but also more bundles identical to those in the prompts. In contrast, the functional analysis reveals a similar use of stance and discourse organizing bundles across proficiency levels and very few referential bundles used by any of the groups. In addition, there were few differences in fixed versus variable slot bundles across proficiency levels. These findings have important implications for instruction and assessment of EAP writing.