The effect of highly focused versus mid-focused written corrective feedback on EFL learners’ explicit and implicit knowledge development

Abstract Research shows that written corrective feedback (CF) can facilitate improved grammatical accuracy in second language learners’ new pieces of writing. However, scholars have not yet identified whether accuracy improvement is a result of the development of explicit knowledge, implicit knowledge, or both. This study examines the comparative effects of highly focused and mid-focused metalinguistic CF on explicit and implicit knowledge of regular and irregular past tense forms. Fifty-eight low-intermediate English-as-a-foreign-language (EFL) learners in a first-year English program at a Thai university were randomly assigned to a highly focused group, a mid-focused group, and a control group. The two treatment groups attended a 4-week intervention, where they completed three story rewriting tasks with an experienced EFL instructor and received respective feedback on their errors. Treatment effects were assessed at a pretest and two posttests using an error correction task, a timed grammaticality judgment test, and a timed picture description task. Results revealed that the highly focused and mid-focused groups significantly outperformed the control group on all outcome measures for regular but not for irregular past tense forms, with no significant differences between the two treatment groups. The findings are discussed with pedagogical implications for similar contexts.