The Role of Feedback Explicitness in L2 Morpheme Acquisition: Evidence from Chile

This dataset contains anonymised accuracy scores from a quasi-experimental study on the effects of feedback explicitness in second language acquisition. Forty first-year English Pedagogy students at a Chilean public university were assigned to three groups: Direct Metalinguistic Feedback (DMF, n = 14), Indirect Metalinguistic Feedback (IMF, n = 17), and Control (n = 9).
Data were collected through three writing tasks and three writing tests (pre-test, immediate post-test, delayed post-test) designed to elicit the third-person singular -s morpheme in English verbs. The dataset includes raw individual scores, group-level descriptive statistics, and outputs from non-parametric tests (Shapiro–Wilk, Kruskal–Wallis, Mann–Whitney U).
All data have been fully anonymised and can be reused for replication studies, meta-analyses, or comparative investigations of written corrective feedback in EFL contexts.