Several assessments conducted within the school's modules employ a multiple-choice format.
The school follows generally-accepted guidance for such assessments and carries out Compensatory Marking (also known as negative marking). This is to ensure that zero knowledge = zero score (within statistical fluctuations) and full knowledge receives a 100% score.
In summary:
- if there are N possible answers to each question, then incorrect answers should be scored with a mark of (-1/(N-1)). Correct answers score +1.
- if questions are of different mark values, then for a question worth M marks, incorrect answers should be scored with a mark of (-M/(N-1)). Correct answers score +M.
- an “I-do-not-know-and-do-not-wish-to-guess” option will always be included as one of the possible answers. If selected, such an answer will score zero.
- the value for N in the formulae above does NOT include the “I-do-not-know-and-do-not- wish-to-guess” option.
Lecturers should explain how the marking works, and advise the students on their best strategy, which is:
- Answer all the questions you think you know (obvious, but a good starting point)
- Selecting purely random answers for a subset of questions should not affect the final mark (within statistical fluctuations) so students should not be penalised if they attempt all questions. Key point: on average a student will gain as many ‘lucky marks’ as they lose from the compensatory marking.
- As soon as students know something which helps them eliminate some wrong possible answers, they change the odds for ‘informed guessing’ in their favour, and they should attempt the question.
- It is generally not in the students best interest to select the “I-do-not-know-and-do- not-wish-to-guess” option unless they are certain they cannot eliminate any of the other possible answers. Even then, the should randomly gain as many marks as they lose.