Public exams have to be fair. It is Ofqual’s job to make sure that candidates get the results they deserve, and that their qualifications are valued and understood in society. Ensuring examination reliability is a key part of this - making sure that candidates obtain a fair result, irrespective of:
- who marks their paper
- what types of questions are used (multiple choice or essay questions)
- which topics are set or chosen to be answered
- when the examination is taken
This consistency of exam results is referred to as reliability: the repeatability of results from one assessment to the next, whether they are assessments taken on different days, or from one year to the next.
In everyday use, ‘reliable’ means ‘that which can be relied on’, but the technical definition in educational assessment is narrower. In assessment, the definition is ‘the extent to which a candidate would get the same test result if the testing procedure was repeated’. The technical definition of reliability is a sliding scale, not black or white, and encourages us to consider the degree of differences in candidates’ results from one instance to the next.