Is This Reliable Enough? Examining Classification Consistency and Accuracy in a Criterion-Referenced Test

One important step for assessing the quality of a test is to examine the reliability of test score interpretation. Which aspect of reliability is the most relevant depends on what type of test it is and how the scores are to be used. For criterion-referenced tests, and in particular certification tests, where students are classified into performance categories, primary focus need not be on the size of error but on the impact of this error on classification. This impact can be described in terms of classification consistency and classification accuracy. In this article selected methods from classical test theory for estimating classification consistency and classification accuracy were applied to the theory part of the Swedish driving licence test, a high-stakes criterion-referenced test which is rarely studied in terms of reliability of classification. The results for this particular test indicated a level of classification consistency that falls slightly short of the recommended level which is why lengthening the test should be considered. More evidence should also be gathered as to whether the placement of the cut-off score is appropriate since this has implications for the validity of classifications.