Stem and lead-in (multiple choice questions)

A.Prof Frank Gaillard et al.

The stem and lead-in are the first parts of multiple choice questions and are sometimes rolled into one short sentence or phrase. 

These have a dual purpose: 

  1. provide context for the question and provide any relevant information
  2. instruct the examinee exactly what needs to be done to answer the question correctly
  • A 45-year-old man complains of back pain and hematuria. [stem]
  • What is the most likely cause? [lead-in]
  • What is the most common cause of hematuria? [combined stem and lead-in] 
  • clear: the stem should be clearly written, and unambiguous; do not try and trick the examinee
  • short: try and keep the stem as short as possible without, however, diminishing comprehension (e.g. avoid acronyms)
  • avoid negatives
    • in most instances, stems should be worded to achieve a positive/true answer, as this reinforces knowledge. 
      • positive: "In what demographic is MS most common?" 
      • negative: "In what demographic is MS least common?"
    • sometimes the learning goal is a negative answer and if this is the case the negative term should be ALL CAPS and emboldened (e.g. "Which of the following is FALSE?") to avoid misreading
    • read more about negative questions
  • avoid double negatives: double negatives are never needed and should be avoided
  • use the present tense
    • generally, the stem should be in the present tense  (e.g. "A 50-year-old male presents with abdominal pain and a CT scan is performed")

When writing the stem, try to stick to a natural order that places content in an order that has maximal readability and limits confusion:

  1. age/sex
  2. relevant history
  3. presenting signs and symptoms
  4. what was done
  5. lead in question

The lead-in follows the stem and is used to instruct the examinee as to exactly what is required to answer the question correctly. It can either be in the form of a question or a phrase needing completion. 

  • question-type lead-in
    • "What is the most likely diagnosis?"
    • "Which of the following is FALSE?"
  • completion-type lead in
    • "The third branch from the arch of the aorta is..."
    • "All of the following are reasonable diagnoses EXCEPT..."

It is essential that for the completion type lead-in, that the alternatives (see below) are phrased in such a way that they grammatically finish the lead-in appropriately – in other words, you should be able to read the lead-in followed by each alternative, and it should make sense. 

Both the stem and lead-in should have normal sentence capitalization and punctuation. There are a few special notes specific to multiple choice questions:

  • question-type lead-ins should finish with a question mark ( ? ) 
    • e.g. "What is the most likely diagnosis?"
  • completion-type lead-ins should finish with an ellipsis ( ... )
    • e.g. "The most common cause of a headache is... "
  • if the lead-in is asking to pick the single wrong answer (negative question) the negative word should in be in ALL CAPS and emboldened, to make it harder to misread
    • e.g. "Which of the following is FALSE?"
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