Exploring Changes in Syntactic Complexity in Students’ Writing through Change Point Analysis: The Case of Clausal and Phrasal Elaboration

Abstract

Studies in L2 (academic) writing have frequently explored the manifestation and development of syntactic complexity at the clausal and the phrasal levels and measured their changes over time (Bulté & Housen, 2018, 2014; Lu, 2017; Verspoor, Lowie, Chan & Vahtrick, 2017; Yoon, 2017). A usual approach to measuring the changes is through comparison, for example between pre- and post-test writing samples, or multiple occasions of writing samples. While this approach has informed our understanding of L2 writing development, it is usually unable to pinpoint the transitional jumps along the developmental pathways. This presentation demonstrates how a change point analysis can be used to fill this gap.

This study analysed 80 academic essays written by 4 advanced L2 student writers longitudinally, which were then coded with a judicious selection of fine-grained measures of clausal and phrasal complexity. Developmental profiling methods were applied to build the linguistic profiles of each participant, followed by a change point analysis (Taylor, 2000) to identify developmental jumps in these measures. These identified jumps were then compared to those identified through the complex method of variability analyses, which included bootstrapping and Monte-Carlo simulation (van Dijk & van Geert, 2007), to check if they concurred.

The results show that the developmental jumps identified through change point analysis align well with those identified through variability analyses. Given that change point analyses can be relatively easier to perform using Change Point Analyzer, it might be a good preliminary step for detection of possible developmental transitions in the dataset before proceeding to perform the more complex variability analyses. This study contributes to better understanding of how clausal and phrasal complexity grows in L2 writing through a detailed description of their changes in students’ writing. It also highlights some important findings which have direct practical implications to the L2 teaching and learning.