Multiple choice questions

Multiple choice questions (MCQs) can be excellent tools for self-learning allowing individuals to identify areas of their knowledge which is weak, as well as allowing the development of metrics to compare oneself with other individuals of a similar level. They are also extensively used in assessment during medical training.

For questions to be useful, however, they need to be well written and adhere to a number of best practices.  

This article covers a number of aspects of this topic as it relates to Radiopaedia.org, including terminology,  types of questions, and best practices. 

Who can create questions?

Multiple choice question creation will be initially restricted so a limited number of individuals, mostly from the editorial board. If you are interested in helping us create questions for the site, and have experience in writing questions please contact us on [email protected]. 

Originality

It is essential, as is the case for all other content on Radiopaedia, that submitted multiple choice questions are both original and of high quality. Please do not copy questions or submit 'recalled' questions from exams. 

Terminology 

An MCQ has a number of parts: 

1. stem:this is the first part of the question, typically contains the most words
2. lead in: follows the stem, and leads into the alternatives and makes it obvious what is being asked of the examinee in this question
3. alternatives (or options):these are usually shorter and offer various options to choose from to answer or complete the stem. 
   • answer (or key): this is the alternative that is correct
   • distractor: these are alternatives (usually 3 to 5) that are incorrect

Types of questions

All multiple choice questions on Radiopaedia are of the "single best answer" type. In other words, each question has only one correct answer out of the 4 to 6 options. This is currently the dominant type of question and is believed to be the most effective by educators. 

Radiopaedia has three specific types of questions, each designed to achieve different educational goals. They are: 

1. basic factual
2. knowledge integration
3. image interpretation

Best practices 

If an MCQ is to be useful it needs to be clear and concise. It can test factual knowledge or require thinking, but for the purposes of Radiopaedia.org, it should be primarily about comprehending the question. The following rules should be followed when authoring questions. 

Stem

Clarity

• 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 diminishing comprehension
• avoid negatives
  • in most instances, stems should be worded to achieve a positive / true answer as this reinforces knowledge. 
    • correct: "In what demographic is MS most common?" 
    • incorrect: "In what demographic is MS least common?"
  • sometimes the learning goal is a negative answer, but this is uncommon
• avoid double negatives: double negatives are never needed and should be avoided

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: "What is the most likely diagnosis?"
• completion: "The third branch from the arch of the aorta is..."

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. 

Alternatives

Each 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.  

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 is the odd-one-out
  • if homogeneity of answers is not possible then have a similar number of alternative 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

Order

Alternatives should be presented in a non-random order. This not only reduced 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. T1, T2, T3, T4, T5

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

Avoid

• 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 some types of clues to be avoided:
  • some terms repeated more often in than others
  • use of 'never' or 'always'
  • repeating words from the stem

Related articlearticles

Each MCQ will be linked to at least one 'related article'. Each

In some instances, a single related article is required. At other times each alternative (see above) should havewill need a relevant article; in many instances, all five.

"Why do incorrect alternatives will have just the one(distractors) sometimes require related articlearticles?" I hear you ask. 

Well, whilst at other times 5 related articles will be needed. A related article to a distractor is not only ok, it is encouraged. 

This hashave many functions: 

1. provide further reading on the topic
2. directly support the answer with appropriate references in the article
3. link the MCQ to an article and therefore allow the question to inherit all sorts of attributes (e.g. system) and knowledge of where it fits into the greater scheme of things
4. allow the question to be viewed from the related article