Negative questions (multiple choice questions)

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Negative questions, also known as odd-one-out questions are a type of multiple choice question in which the correct answer is the one that is false, surrounded by true distractors. For example:

Question: Which of the following statements about Onodi cells (sphenoethmoidal air cells) is INCORRECT?

  • Onodi cells are important due to their location in close proximity to the optic nerves
  • Onodi cells are synonymous with "aeration of the anterior clinoid process" [correct answer]
  • Onodi cells are the posterior-most ethmoidal air cell
  • Onodi cells pose an operative risk if their relationship to the sphenoid sinus is not appreciated
  • Onodi cells are located superolateral to the sphenoid sinus

For the purposes of examination these types of question are generally frowned upon for two reasons:

  • it is possible for examinees to misread the question and attempt to identify the most correct rather than false alternative
  • it is hard to prove a falsehood

    • Although both of these criticisms are valid, particularly in the exam setting, there are many situations in which this format is desirable. For example:

    Question: Which of the following medulloblastoma subgroups is LEAST common?

    • group 3
    • group 4
    • sonic hedgehog (SHH)
    • wingless (WNT) [correct answer]

    In the above example, the incidence of group 3, group 4 and sonic hedgehog subtypes is roughly equal (about 30% each, depending on the publication). The wingless group is definitely the least common.

    Best practices

    Before writing a negative question, ask yourself the following questions:

    • can this be rephrased as a positive question?
    • is the fact that one of the options is incorrect/false explicitly supported by the related articles? 

    Style

    In all of these questions, to minimize the risk of misreading, make sure the negative word is in ALL CAPS and emboldened. For example

    • Which is the LEAST common...
    • The following are features EXCEPT... 
    • Which of the following is INCORRECT?