Comparison of collaborative self, peer and tutor assessment in a biochemistry practical

Abstract

Introduction It has been noted that Higher Education often falls short of its own aims of promoting effective learning, indepen- dence of thought, awareness of alternative approaches to a subject and rational debate. 1 In looking for reasons for this failure, one area of student experience which is being examined is the traditional method of assessment within which staff members exercise unilateral intellectual authority. Undergraduate students entering into univer- sities normally follow a pre-designed programme of learning into which they have no input; they are subjected to pre-determined criteria of assessment without necess- arily being informed about the nature of these criteria, and they have little say in the judgements which are made about them by lecturers and tutors. This situation engenders in students a strong tendency to indulge in surface learning by rote such that the perceived essential facts can be memorised for the purpose of 'passing the exams' rather than engendering a commitment to effective learning processes required to give a deep understanding of the given subject. The traditional system of assessment therefore generates the wrong sort of motivation in students through its emphasis on external rewards and punishments. The system also militates against the notion of developing students' ability to evaluate their own work in ways which are applicable to their future professional work in any given discipline. One possible means of changing the status quo is to make assessment procedures an integral part of the learning process since life-long learning requires that individuals are able not only to work independently but also to assess their own perform- ance and progress. Involvement in the assessment process would hopefully heighten our awareness and knowledge of the student approach to learning and enable students to make rational and objective judgements about their own strengths, weaknesses and range of skills. As previously described by Falchikov, 2 alternatives to traditional assessment practices have fallen into three categories: self assessment, peer group assessment and collaborative assessment. In self assessment the learner judges his or her own performance and products against his or her own criteria. In peer group assessment, peers assess the learner with or without prior discussion, and collaborative assessment requires that learner and tutor discuss and negotiate a commonly agreed set of assess- ment criteria and the final assessment grade. This paper describes an experiment in collaborative peer and self assessment of a first year undergraduate biochemistry laboratory practical experiment. Procedure A laboratory practical project entitled 'Chemical Frac- tionation of Cells and Estimation of Nucleic Acids and Protein' has been used over many years with varying degrees of success. The experiment involves separation of nucleic acid and protein components of a rat liver cell suspension using straightforward extraction procedures followed by colorimetric assays. Students work in pairs with the occasional group of three students working together. The practical is carried out over two three-hour sessions. In this instance, prior to the students coming to the laboratory there was a one-hour discussion period with the primary aim of introducing the students to the concept of involving themselves in the assessment procedure. The first class of 87 students agreed to self-assessment of the practical report. A class representative then agreed to start negotiating with the rest of the class on the key points which would be important for a good report. Thecriteria were then ranked in order through continual discussion and student assignment of a points system. The role of the tutor in this was one of encouragement and support for the students and helping to put issues to a vote if this was deemed necessary. By the end of the discussion period a marking system had been devised with which the class was happy and over which the students had full ownership. A second class of 63 students agreed to peer assessment of the practical report and again a class representative initiated the negotiation phase. This class also decided on the important points which should be made within the report and devised a scoring scheme. Interestingly the two classes decided on different weightings of the marks but to give a true sense of ownership of the assessment criteria no adjustments were made by the tutor. Results (1)