How reliable and valid is peer evaluation in adolescents’ L2 argumentative writing?

Peer evaluation is widely recognized for its educational benefits; however, its reliability and validity, particularly among adolescent second-language (L2) writers at the early stages of English language and literacy development, remain insufficiently explored. This explanatory sequential mixed-methods study investigated the reliability and validity of peer evaluation in English argumentative writing among 35 Grade 10 and 37 Grade 12 students from a public high school in Beijing, China. Twelve of the participating students (six at each grade) were interviewed about the validity, reliability, and value of peer evaluation. The findings indicated that peer evaluations demonstrated high levels of reliability and validity, with peer-assessed writing scores closely aligning with inter-teacher assessments. Notably, variations were observed among Grade 10 students, particularly in the evaluation of lower-order writing skills, such as grammar and vocabulary, which exhibited reduced validity. These results underscore the potential of peer evaluation in assessing higher-order content-level writing across varying levels of L2 English writing proficiency. The study also highlights areas where adolescent L2 writers may require additional support to enhance the effectiveness of peer evaluation practices in English argumentative writing. Implications for improving English argumentative writing instruction and refining peer evaluation strategies in high school L2 English classrooms are discussed. • Peer evaluation shows high reliability, similar to inter-teacher rating. • Peer evaluation works well for higher-order skills in L2 argumentative writing. • 10th graders struggled with evaluating lower-order skills like grammar. • 12th graders evaluate lower- and higher-order skills with greater validity than 10th graders.