Alternatives (multiple choice questions)

Last revised by Daniel J Bell on 5 Sep 2019

Alternatives are part of multiple choice questions, comprising the options from which an examinee must choose the correct answer. 

Each multiple choice question should have, ideally, 5 alternatives, one of which is the correct answer (the "key"). In some instances, 5 options are not appropriate, and 4 - 6 options are acceptable.  

Best practices

Length and content
  • short
    • alternatives should be as short as possible with the majority of the text in the stem
    • if a term is going to be repeated in each alternative, then it should be moved into the stem or lead in
  • similar in length
    • should all be approximately the same length
    • have similar language and grammar to avoid inadvertent clues
  • similar content
    • should be similar in content and phrasing to avoid one alternative clearly as the odd-one-out
    • if homogeneity of answers is not possible, then have a similar number of alternatives for each type (balanced)
  • similar scale
    • if numbers are used in the alternatives, they should all be in the same unit of measure
  • non-overlapping ranges
    • avoid overlapping numeric or verbal ranges  i.e. 0-5, 5-10 (5 is repeated). Instead, use 0-5, 6-10.
  • balanced alternatives
    • If 3 alternatives have the word aorta in it, then you probably need 3 other alternatives with a repeated word to ensure that no clue is present

Alternatives should be presented in a non-random order. This not only reduces cognitive effort in parsing the alternatives but also enforces a more random selection of the correct answer. 

For sets of alternatives that have a natural order, this should be in ascending order. Examples include:

  • values: e.g. 2, 6, 8, 12, 20
  • ranges: e.g. 0-5, 6 -10, 11-15
  • density/intensity: e.g. hypodense, isodense, hyperdense
  • anatomic: e.g. head, neck, chest, abdomen, pelvis

When no such natural order exists, then answers should be presented in alphabetical order. 

  • compound answers: alternatives such a "B & C" or "A, B and D" are to be avoided
  • all or none of the above: it is generally better to have fewer alternatives than to add filler alternatives such as these
  • silly or obvious alternatives: obviously correct or obviously incorrect answers, even if humorous, detract from learning
  • clueing: the correct answer can be guessed without any actual knowledge of the topic. Examples of some types of clues to be avoided:
    • some terms repeated more often than in others
    • use of 'never' or 'always'
    • repeating words from the stem


The style of alternatives should be similar to that of bulleted and numbered lists for the rest of Radiopaedia. In other words, they should not be capitalized (except if a proper noun or acronym etc...) nor should they end with full stops. 

The exception to this rule is if each alternative is a complete sentence or if the question is a 'complete the sentence' sort of question (i.e. where the stem finished in ... ). 

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