Peer assessment in higher education has been studied for decades. Despite the substantial amount of research carried out, peer assessment has yet to make significant advances. This review identifies themes of recent research and highlights the challenges that have hampered its advance. Most of these challenges arise from the manual nature of peer assessment practices, which prove intractable as the number of students involved increases. Practitioners of the discipline are urged to forge affiliations with closely related fields and other disciplines, such as computer science, in order to overcome these challenges.