Stem and lead-in (multiple choice questions)

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 dual purposes: 

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

Examples

Example 1: separate stem and lead-in

• A 45-year-old man complains of back pain and hematuria. [stem]
• What is the most likely cause? [lead-in]

Example 2: combined stem and lead in

• What is the most common cause of hematuria? [combined stem and lead-in] 

Best practice

Stem

• 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 in 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")
• avoid teaching: questions are questions, not didactic teaching. Therefore avoid including non-question specific facts within stems. 

Content order

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

Lead-in

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. 

Style

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 be in ALL CAPS and emboldened, to make it harder to misread
  • e.g. "Which of the following is FALSE?"