Individual Differences and Task Complexity in Second Language Writing: A Methodological Review

ABSTRACT

This article provides a methodological review of empirical studies on second language (L2) writing and task complexity that have investigated the role of learner individual differences (IDs) in L2 writing processes and outcomes. Thirty journal articles published between 2005 and 2025 were coded for key theoretical, methodological (including ID measurement and analytical practices), and contextual characteristics. We identified thirty researched IDs, with L2 proficiency, working memory capacity, and L2 writing anxiety emerging as the most commonly investigated. Expanding insights from previous methodological reviews in task‐based language teaching (TBLT) (e.g., Bryfonski et al. 2024; Plonsky and Kim, 2016), we pinpoint and discuss common practices in theoretical orientation, ID instrumentation, overall study design, task design and implementation, and coding and analysis, among others. We also provide methodological recommendations in various domains and highlight promising avenues for future research.