Expanding insights of vocabulary knowledge, metacognitive knowledge, and reading in Teng (2025)

Responding to Teng’s (2025a) longitudinal research on metacognitive knowledge (MCK), breadth of vocabulary knowledge (BVK), and reading proficiency in young EFL learners, this article expands the theoretical and pedagogical framework by addressing underexplored dimensions of developmental dynamics, cognitive-affective moderators, and ecological validity. Conceptually, it advocates for a Dynamic Systems Theory (DST) approach, emphasizing non-linear, recursive trajectories of metacognitive and vocabulary development, especially among early-stage English as a Foreign Language (EFL) learners. Methodologically, the paper proposes multivariate, longitudinal designs—including latent profile analysis (LPA) and cross-lagged panel analysis (CLPA)—to capture intra-individual variability and clarify conditional interactions among morphological awareness, reading fluency, and affective variables. Pedagogically, it underscores embedding metacognitive strategy instruction (MSI) within authentic classroom ecologies, highlighting differentiated, scaffolded instructional practices tailored to learners’ cognitive and affective profiles. Integrating these dimensions bridges theoretical insights and practical pedagogical strategies, contributing to nuanced, ecologically valid models of vocabulary-mediated reading development.