Peer review is a powerful way to develop expertise in the discipline. It starts from the premise that making evaluative judgements about work against standards is an important skill. This skill is required in professional practice and for life beyond university but it is not usually explicitly taught in university. Peer review can also help underpin the development of critical thinking and enquiry-led learning. From the literature, different reasons are discernable for introducing peer review. Those most common reason is to enhance the feedback that students receive, to develop their writing skills, to put them in the role of the assessor so they know what the teacher has to do and to develop judgement. [see, Gielen, Dochy, Onghena, Struyven and Smeets, 2011)

In these web pages we are not promoting peer marking often called peer assessment. Not only do staff have some problems with this but so do students. In two recent implementations reported in this website(Engineering Design and Sociology) the majority of students in an online survey expressed concern about being asked to mark other student's work. Also, if students do mark or even rate the work of others and then the teacher provides marks that are quite different from those of the students then this undermine the value of peer review in the minds of students. The sitution is quite different if students are required to produce written feedback of some kind - a suggestion for improvement, a reaction to what is written etc. Most students respond positively to this and to a process where they see the range of work produced by their peers.

The purpose of peer review is to develop these skills. Hence it might be wise to start with a task which is manageable and students can begin to develop these skills and then to proceed to more complex tasks. Also, if the review questions are set at the right level (e.g. say how you think the argument in the essay might be strengthened) students will be able to make some contribution and it will help them think more deeply. Another strategy is to scaffold the review process by providing students with a menu of ideas that might help them provide a review but leaving some things open to the students. One tested strategy in Biochemistry was to provide students with a menu of questions that teachers might ask about the work.The result was that this menu helped students think more deeply about the peer answer and to formulate better feedback than they might have done without this support.

Most people think about peer review as criticism or as finding weaknesses in the work of peers but this need not be the case. In peer review students might be asked to summarise the work of peers in a few sentences (e.g. an essay), to make a suggestion for improvement, to suggest another solution pathway, to suggest something that could usefully be added. The list is endless and depends on the discipline, the skills you wish to invoke in the peer review task and the overall purpose.

This will depend on purpose and the disciplinary context. Nicol (2013) identifies three principles that are important in relation peer review criteria.  He first discusses these principles in relation to self-review where students review their own work.then extends this to include peer review. Taking the position that the purpose of peer review is to develop students capacity to make evaluative judgements and through this to build new knowledge his first principle is that students should have many opportunities to evaluate work from reference points different from those from which the work was produced. So for example, the review criteria might call on students to summarise the work of peers, to identify hidden assumptions, to explore alternative perspectives on an issue, to identify the centre of gravity in a piece of writing or the most compelling argument or most convincing evidence.   

His second principle is that evaluation criteria should tap into the subject domain in ways that help develop disciplinary thinking (even though they might also go beyond a single discipline, for example, if the course aim is to foster inter-disciplinary thinking).  From a disciplinary perspective, students might, for example, make judgements about the merits of different design decisions in engineering, about the soundness of a diagnosis in medicine, about the most elegant solution in mathematics or about the validity of decision-making in social work or in business.  The third principle is that students should have opportunities to formulate their own criteria for reviews so that they have experience in deciding on what kinds of evaluative criteria are important. This is essential if students are to become autonomous and lifelong learners able to set their own goals and evaluate their progress in achieving them. 

Peer review is a developmental process - it is a means of helping students to learn. They learn the skills of producing feedback, required in professional practice and they learn from the feedback they receive. One could ask the same question about the provision of teacher feedback - if students use this is it not plagiarism? A lot rests on how peer review is integrated into a course and specifically on the peer review sequence and activities.  For example, imagine the target for the review task was an essay but different groups of students wrote essays on different topics, and they also reviewed an essay on a topic that they had not written about, then this would minimise plagiarism but still leave room for learning transfer. There are numerous ways of dealing with this plagiarism issue but what is important is not to discourage collaborative learning nor to undermine student development. If plagiarism avoidance is an over-riding concern the simplest approach is to make sure that the summative assessment (e.g. final work carried out for marks) is different from the peer review activity, although by necessity it will always draw on the skills developed through that activity.