Background: Peer-marking has been suggested as a method to enhance self-directed learning and reflection, although whether this improves performance is unclear. This study evaluated the impact of peer-marking on examination performance and investigated its reliability and acceptability to students.
Methods: First-year medical students were randomised to peer-marking using a model answer or no intervention (control arm). Student scores were compared with tutor-marked scores. Two months later, students completed a summative assessment and performance was compared between students randomised to peer-marking and the control arm. A focus group was held with students in the intervention arm to capture their experiences and attitudes.
Results: A total of 289 of 568 students consented to participate and 147 were randomised to peer-marking (142 controls). Students randomised to peer-marking achieved marginally higher examination marks (1.5% difference, 95% CI -0.8% to 3.9%, P = 0.19) than controls (adjusting for year and in-course assessment), although this may have been due to chance. Students were harsher markers than the tutors. Focus group analysis suggested that students valued peer-marking, although concerns about passing judgement on a colleague's work were expressed.
Conclusions: Peer-marking did not have a substantial effect on examination performance, although a modest effect cannot be excluded. Students gained insight into examination technique but may not have gained deeper knowledge. Given its potential positive educational value, further work is required to understand how peer-marking can be used more effectively to enhance the learning experience.