Peer Feedback Training in L2 English Writing: A Systematic Literature Review of Empirical Studies from 2016 to 2025
Although peer feedback has been widely used in second language (L2) English writing instruction, its pedagogical value is often constrained by vague comments, limited understanding of evaluation criteria, low learner confidence, weak peer trust, and insufficient uptake of revision. Guided by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses framework, this systematic literature review identified and synthesized empirical studies published from 2016 to 2025 on peer feedback training in English as a Foreign Language and English as a Second Language writing contexts. Database searches in Scopus, Educational Resources Information Center, and Web of Science were followed by deduplication, title and abstract screening, full-text eligibility assessment, and quality appraisal. Nineteen empirical studies were included in a narrative thematic synthesis focusing on instructional design, reported learning outcomes, and implementation challenges. The synthesis suggests that peer feedback is more effective when supported by rubrics or checklists, teacher modeling, guided peer-review tools, peer dialogue, AI-supported scaffolding, and revision-reflection tasks. Reported outcomes included improvements in feedback quality, revision uptake, writing performance, feedback literacy, motivation, self-efficacy, engagement, and self-regulated writing. Recurring implementation challenges included uneven learner readiness, limited feedback specificity, insufficient peer trust, time constraints, and the need for teacher monitoring and systematic guidance. Based on these findings, the review proposes a lightweight peer feedback training framework for L2 writing instruction and future intervention research.