Peer assessment is a promising approach for improving writing skills and reducing instructors' workload in writing-to-learn classes. Although peer assessment provides educational benefits, its adoption is limited due to methodological issues in prior studies, such as uncontrolled variables. Therefore, this study aimed to empirically examine whether writing with peer assessment improves writing performance, regardless of initial writing skills and academic levels, in controlled experimental settings. Thirty-eight undergraduate students were assigned to the experimental condition, writing and assessing other students' writings on three topics before a final writing task. Another thirty-five students in the control condition only completed the final writing task. Analysis revealed that the participants of the experimental condition outperformed those of the control condition, irrespective of participants’ initial writing skills and academic levels. These findings suggest that writing with peer assessment could be a promising instructional approach for improving writing skills among students of varying abilities. 

Keywords : academic level, peer assessment, writing, writing performance, writing skill