A review of the idiodynamic method in second language learning and teaching research

Abstract Research on Second Language (L2) teaching and learning has increasingly acknowledged that key psychological and linguistic processes fluctuate over time rather than unfold as stable traits. The Idiodynamic Method (IDM) was developed to capture such moment-to-moment variability, yet its applications remain conceptually scattered and methodologically uneven. This review presents a PRISMA-guided narrative synthesis of 24 IDM studies to examine the constructs of L2 learning and teaching to which the method has been applied and how it has been designed and implemented to capture dynamic change. Results show that across psychological, emotional, linguistic, and pedagogical constructs, IDM reveals fine-grained intra-individual patterns shaped by task demands, contextual conditions, and learners’ subjective experience. The study also identifies substantial diversity in rating intervals, scale design, and analytic integration, underscoring that methodological choices are epistemological rather than merely technical in nature. Framed as an explanatory sequential mixed-methods approach, IDM enables researchers to examine the waves of L2 development rather than only its global outcomes. The review concludes by outlining principled directions for methodological refinement and future applications beyond speaking-focused research, including attention and classroom participation.