I have edited a lot of multiple-choice questions (and seen several more throughout my own education). Here is a guide I’ve put together about how to create good multiple-choice questions and avoid creating bad ones.
Obviously, make sure the question and answer are correct. Less obviously, make sure none of the distractors (wrong answers) are also correct.
Be clear. Make sure the question is unambiguous, and make sure it’s not unintentionally misleading. In particular, if the question is worded in the negative (“Which of these statements is not correct?”) or you want the answer given in an unexpected way (“Put these numbers in order from highest to lowest”), put the “not” or “from highest to lowest” in bold, capitals, or both. It’s not supposed to be a “gotcha” – it’s supposed to be testing knowledge.
Conversely, there are some pitfalls that make the questions easier than you intended – which means, as before, that they’re not accurately testing knowledge.
For example, don’t make the questions answerable based on just the wording of the question and a little common sense, without needing any knowledge of the subject matter. One of the worst examples of this I’ve seen was something like:
Which of the following is an advantage of the flurbleworble process?
A) It’s very accurate
B) It’s very expensive
C) It creates a lot of pollution
D) It requires specialist equipment
Of those options, only A) is an advantage, and the others are disadvantages. The question can be answered without having any idea what the flurbleworble process is or what its advantages and disadvantages are.
Another way of inadvertently making the question easier than you intended is to give answer options which function as a “checklist” for things students typically forget. For example:
Evaluate ∫ sin x dx.
A) cos x
B) –cos x
C) cos x + C
D) –cos x + C
If this were a short-answer test rather than multiple choice, a middling student might answer “cos x“. Here, the set of answer options, rather than serving their intended function as distractors, remind the student “Don’t forget the minus sign! Don’t forget the + C!”
Another pitfall to avoid is making it possible for students to rule out some or all of the distractors on logical grounds. For example:
What is the mass of ball B?
A) Less than 1 kg
B) Less than 10 kg
C) Exactly 10 kg
D) More than 5 kg
Assuming there is only one correct answer, it cannot be A, because then B would be true as well; and it cannot be C, because then D would be true as well. Without looking at the data or doing any calculations, the only sensible answers are B and D.