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Send to friendAssessing a practical task and peer evaluation of that task
Practical class
Peer evaluation
While the ability to evaluate a peer's work is a very valuable skill for students to acquire, attempts to test this, particularly in a laboratory assessment task, often create more problems than they solve. Charges of unfairness and bias by one group of students over another as well as the view expressed by many students that they don't feel "qualified" to mark their peers' work (particularly if this mark counts towards final marks) all can contribute to making the whole exercise an unhappy experience for both students and staff alike. Some students even view the whole exercise as laziness on the part of the academic.
To overcome these problems we present an exercise, run over 3 - 4 laboratory sessions which gives students the opportunity to evaluate another group's work with clear and concise guidelines in a non-threatening environment. Over the first 3 sessions, students explore, develop, optimize and produce an enzyme-linked metabolite assay kit (ELMA) similar to commercially available kits. For example, to measure the level of sugar, alcohol, MSG or lactate in selected foods or drinks. As well as the chemical solutions, students also produce specifications booklets with instructions, trouble-shooting guides and calculation instructions. The kits are packaged (often very attractively) and then marketed to their peers who must test them for both accuracy and ease of use.
The clear-cut nature of the task provides the evaluating students with objective criteria from which to appraise their peers' work. (See marking scale below). Marks are awarded to the evaluating students for constructive comments, criticism and suggested improvements. The feedback from the evaluating students is a great aid to the marker and it should be emphasized that the final mark is actually given by the demonstrator. This exercise rewards the students doing the evaluating, rather than allowing the evaluating students to give their peers a mark that counts toward a final assessment. Because of this some of the less desirable issues of bias and conflict between highly competitive assessment-driven students are avoided.
Student understanding of the theoretical principles behind the ELMA design has been tested extensively in final examinations over a number of years and students, on average, perform well at these questions (above the mean of the whole exam). The whole exercise is viewed very positively; students put a lot of effort into producing their kits and certainly take the evaluation very seriously. This general student attitude and the lack of complaints suggest this approach gives students the opportunity to evaluate peer work objectively without the ill feeling.
The future directions are driven somewhat by the students. With each year new ideas are incorporated into the kit, new foods are trialed and the presentation styles are as varied as the students. Over time the focus of the evaluation has changed (largely as a result of new technology) and the criteria have been adjusted but the principle remains.
