Comparing difficulty of GCSE tiered examinations using common questions

Abstract

In tiered GCSE examinations the overlapping grades in the two tiers, C and D, are intended to represent the same level of performance, irrespective of the tier on which they may be achieved. A comparison of the performance of candidates at the overlapping grades can be used to maintain standards between the two tiers. One way this can be done is to include questions that are common to both tiers. In this study we investigated the difficulty of the common questions between tiered question papers to gather evidence of whether the tiered papers were functioning as expected or not. We also explored ways in which the analyses could feed into the process of writing questions for tiered examinations and thereby help in improving the current practice of producing such question papers.