When can a case be made for using fixed pass marks?

Abstract

Using fixed pass marks (e.g., "To pass you must gain 70% of the available marks") has many attractions in some assessment contexts, (e.g., on-demand testing). The obvious drawback to using fixed pass marks is that it does not allow for the fact that test forms may vary in difficulty despite best efforts to construct or design them to be similar. The aims of the research described in this article were to investigate how serious a problem this might be in practice, and to explore the extent to which it could be alleviated by using expert judgement in the test construction process.