ABSTRACT
‘Certainty-based marking’ is a strategy used in self-tests and exams to encourage students to think about how reliable each answer is in objective tests. By always asking ‘How sure are you?’, with a proper scheme of rewards and penalties (1, 2, 3 for correct answers and 0, –2, –6 for incorrect answers with increasing levels of certainty) it rewards honest reporting and yields clear benefits. It stimulates deeper thinking – rewarding identification of sound justifications or reasons for uncertainty. It promotes understanding (awareness of relationships between items of knowledge) and enhances recall. It highlights confident misconceptions (serious impediments to further learning) and, unlike conventional marking, it favours knowledge over lucky guesses. Certainty-based marking enhances statistical reliability in exams and has proved popular with medical students both in self-tests and exams. Perhaps most important is the enhancement of learning with certainty-based marking self-tests. It is argued that such self-tests should be available to students to explore in private, making mistakes and finding strengths and weaknesses without (if they choose) submitting any data to the view of teachers. Certainty-based marking may raise or diminish a student’s initial self-confidence, but it does this by helping them identify and work on areas of sound and weak knowledge.
