10 Tips for Writing Great Multiple Choice Questions (MCQs)

Whilst some people disregard the Multiple Choice Question (MCQ) exam format as being ’too easy', it is being increasingly used in all areas of education, from secondary to university and even professional education. This is at least partially because it allows marking to be automated, but there are a number of benefits the system offers students, and contrary to popular belief, well-constructed great MCQs can test high-level thinking and problem solving skills rather than simply being a test of fact recall.

This guide is for educators and students wanting to know how to write good, challenging MCQs, which we believe is a great way to study and reinforce knowledge.

At a Glance

Anatomy of a Multiple Choice Question. 

Let’s take the following example question:

 "John is a 68 year old man complaining of chest pain. Which of the following tests would be most appropriate to order first?” 

  • A) An electrocardiogram (ECG)
  • B) A chest X-ray
  • C) A DXA scan
  • D) A cardiac stress test

This is a fairly standard multiple choice question we might expect to see on a multiple choice medical exam such as the USMLE, consisting of:

  • A ‘Stem’ (the question or scenario)
  • Distractors (the wrong options)
  • A Key (the right answer)

The beginning part of an MCQ is referred to as the ‘stem’ because it isn’t always a ‘question’ in the strict sense of the word, and students could be asked to fill in a missing word or, as with the question above a brief scenario or case study may be presented alongside the question.Now that you know what the terms are, let’s jump in to our top tips for writing good questions! These are based on years of experience writing tests and evidence from professional educators which we’ve referenced at the end. So in no particular order...

Tip 1: Just have ONE correct answer

A number of formats encourage users to ‘select ALL options that apply’, and do not disclose to students how many correct answers there are. This is a fairly lazy way to construct multiple choice questions, and it doesn’t allow you to isolate functional units of understanding to test them.

Tip 2: Present options in an alphabetical or numerical order

If you don’t follow this rule, then you’re opening your test results up to be biased towards certain positions.

Tip 3: Choose a specific piece of knowledge that you want to test

One advantage of traditional testing methods is that you can ask quite broad questions. Consider for example writing a test for  chemistry students. One large area you would want to test is students’ knowledge of how the periodic table was developed. So you could simply have a question that said:“Write 2-3 paragraphs on the history of how the periodic table was developed” (15 marks)On your mark scheme, you would know what you were looking for and could give, say 2 marks if the student correctly identified Dimitri Mendeleev as the inventor of the ‘modern’ periodic table, 1 mark if they pointed out that this was the first time atoms were arranged in order of atomic number etc.
With MCQs, you are testing much smaller and more focused pieces of knowledge with each question. Furthermore, there can be no ambiguity or room for argument in the question. For example, a very simple MCQ that tests a student’s knowledge of the periodic table would be:Who developed the periodic table?

  • A) Mendeleev
  • B) Lavoisier
  • C) Newlands
  • D) Hinrichs

To anyone studying chemistry, Mendeleev is the obvious ‘key’ here as he is most commonly credited with developing the modern periodic table, but each of the other ‘distractors’ all played their own crucial roles, and the question “Who developed the periodic table?” is not as clear-cut as it first seems, there are many scientists and historians out there who would put forward arguments that Newlands was deserves credit as the ‘real’ inventor of the table.
This creates multiple problems: Firstly, you are punishing ‘more-able’ students who have done extra background reading and understand the question’s ambiguous nature, and rewarding students who have simply remembered that ‘a Russian-sounding guy made the periodic table’. This is a key point and one you should bear in mind when creating any MCQ: You are asking questions in a completely closed format, so make sure there is no ambiguity and that knowledge is being rewarded appropriately. You’ve probably already realised, therefore, that a better stem would be:“Who is most commonly credited with having developed the modern periodic table?”

It’s a subtle but crucial difference: you have unambiguously defined the question, and it’s clear to which piece of knowledge is being tested here. Think of this as analogous to effectively isolating different muscle groups during weight training.

Tip 4) Questions should be self-contained

Questions should be self contained in a multiple choice exam. In other words, you shouldn’t have two questions that follow on from each other (i.e. where it is necessary to have answered the first question in order to attempt the second), but a more subtle problem, and one that people seem to miss out quite frequently is exemplified below:
Question 1) What type of animal are dolphins?
  • A) Fish
  • B) Mammals
  • C) Amphibians
  • D) Reptiles
Question 2) Which of the following is NOT true about dolphins?
  • A) They are cold-blooded
  • B) They are closely related to whales
  • C) They belong to the same class of animal as elephants
  • D) There are considered to be highly intelligent animals
Now, each of these two questions are fine by themselves, but when you put them together, several problems come into focus. Firstly, whilst they are phrased very differently, there is actually a significant overlap between the areas of knowledge they are testing, meaning that putting both of these questions in a test is slightly inefficient, especially when these exams have only a limited number of questions to test what are usually very large subject areas. To put it another way, it’s very likely that if a student knows the answer to question 1, they will also know the answer to question 2. The two questions do test some distinct areas, but there is almost certainly a better way to address this.The second problem, and the main one I want to discuss in this section is that a student’s answer to one is heavily linked to their answer to the other. If, for example, a student rightly believes that dolphins are mammals, then he or she has gained not one, but two marks as whilst it doesn’t completely give them the answer, it gives them a significant advantage in answering question 2. For lovers of formal logic: The student knows that A = B and B = C, therefore they can ‘deduce’ that A = C.

Tip 5) Avoid ‘Easy’ (non-functioning) Distractors

The distractors in a multiple choice exam play a large role in determining how hard the exam is. Let’s take the question below:

 “Of the following options, who is commonly credited with the invention the lightbulb?”

Unless you happen to very confidently know the correct answer, how hard this question is largely depends on how hard it is to eliminate the distractors. People writing tests often draw the distinction between ‘functioning’ versus ‘non-functioning‘ distractors. A so-called ‘non-functioning‘ distractor is basically a filler option: officially defined as a distractor which is selected by less than 5% of students, they are answers that are obviously wrong, as shown in the ‘easy’ example below:- A) Thomas Edison

  • B) Fred Flintstone
  • C) Selma Hayek
  • D) Steve Jobs Even if you have never heard of Thomas Edison, it is very easy to know the correct answer here simply by eliminating the ridiculous, non-functioning ‘distractors’.
Now let’s make it a bit harder:
  • A) Thomas Edison
  • B) James Watt
  • C) Benjamin Franklin
  • D) Alexander Bell

 

Suddenly, the same question is made much harder as none of the names here are immediately out of place: each person here made some contribution to the field of ‘early electricity’.

The crucial difference between functioning and non-functioning distractors is that they’re what allow you to separate your ‘more-able’ from your ‘less-able’ students. In both versions of the lightbulb question, an able student will know that Edison invented the lightbulb, and therefore can answer the question without paying too much notice to the distracters at all. On the opposite end of the spectrum, your least-able students won’t have a clue who invented the lightbulb, but they’ll probably know it wasn’t Fred Flintstone, Selma Hayek or Steve Jobs: so despite not having the knowledge, they will still be able to claim the mark in the first question. Only the second question really tests whether or not this student knows who invented the lightbulb.

A lot of exams seem to include a mixture of functioning and non-functioning distractors for a given question, leading to a common (and possibly not completely untrue!) adage that in MCQ exams ‘there are always two daft options you can eliminate instantly, so really you have two choices’. Try to resist the temptation to do this: thinking of distractors is a time-consuming process, and whilst having more distractors appears to make the test more difficult superficially, in reality it doesn’t, as students can pick them out with ease. Which brings us on to our next point…

Lesson 6) Distractors should be picked for good reasons

We’ve already established that you should aim to create functioning, rather than non-functioning distractors in your questions: this simple rule will be enough to stop your questions being bad, but it won’t necessarily make them good! To really effectively answer the question “Does this student know and understand this point?”, your distractors should address specific misconceptions about a particular question, for example:What is the most commonly fractured bone in the human body?- A) The clavicle

  • B) The hip
  • C) The ankle
  • D) The scaphoidThis is a good question as it is unambiguous, and consists only of functioning distractors.

There is only one correct answer here (the clavicle, or ‘collar bone’), but each of the other options are also commonly fractured, and the fact that each of them are liable to fracture in specific circumstances is a key fact students will learn about them. Hip fractures, as you will know are a very common and serious disability occurring mainly in elderly women. In fact, in this sub-group they are probably the most fractured bone by far, which may throw off some students who don’t have all their facts straight.If we changed the distractors, for example to other bones such as ‘Tibia’ (in your shin) or ‘Cranium’ (skull), whilst they are probably still ‘functioning’ distractors, they are a lot easier to rule out as unlike the distractors in the first question, these are not addressing any particular pitfall or misconception that a lot of students may falsely believe, and therefore the question is not going to differentiate ‘more able’ from ‘less able’ students in the same way.

Lesson 7) Avoid committing to words such as ‘never’ or ‘always’

This is a simple one: when phrasing your questions, try to stay away from ‘categoric’ words or phrases that don’t leave any wiggle-room such as ‘never’ or ‘always’. They can either make a question too obvious, or they can render it ambiguous and open to argument. Consider the following question (it’s another medical one so apologies if you’re a non-medic, but I try to keep them accessible and ultimately if there’s anything I don’t explain about them its simply because that detail is actually irrelevant!)

Which of the following is NOT a side-effect of aspirin?

  • A) Dry cough
  • B) Tinnitus
  • C) Stomach ulcers
  • D) Spontaneous bruising

Medical students will know what the ‘correct’ answer here is straight away, for non-medics: Tinnitus, stomach ulcers and spontaneous bruising are very well-known and fairly specific side effects for aspirin, if someone on aspirin came to you presenting with one of them then aspirin would probably be your first suspect. A cough, on the other hand is not really associated with aspirin (although other common drugs can cause a dry cough).
Dry Cough isn’t a bad distractor by any means, as dry cough is the main side effect of another well-known class of drugs often taken in conjunction with aspirin, so it’s perfectly valid to test whether the student can accurately differentiate between the two. So what’s the problem?
‘is NOT’ is a very categorical statement. If that student happens to have done a lot of extra research on the side effects of aspirin, its perfectly possible that he knows of an obscure article somewhere with evidence that aspirin can cause a dry cough. In reality, the student at this level should know the ‘correct’ answer despite this by deciding which is the ‘least incorrect’ answer, but still why not absolve yourself of blame and angry, pedantic emails after the exam by rephrasing it to:

‘Which of the following is not a typical side-effect of aspirin?’

Tip 8) Be consistent in choosing your distractors

If you’re going to use ‘All of the above’ or ‘None of the above’ answers, make sure you use them consistently throughout the test and not just on a handful of questions: if you only use it in a few questions then it’s a dead-giveaway for students that it’s the right answer, and even if you’re actually using it as a distractor it can mislead students who would otherwise have picked a different answer they were reasonably confident in.Similarly, bear in mind that if ‘All of the above’ is present as an option, then identifying one distractor is enough to eliminate it as an option, and similarly identifying correct answers is enough to identify it as the key. (a)Another pitfall that you’ve probably seen yourself is inconsistent distractors within a single question. Consider the following question:When considering treatment options, doctors should take into account all of the following EXCEPT:

  • A) The physical, mental and social wellbeing of their patients
  • B) The safety and effectiveness of the pharmaceutical, surgical or other treatments they prescribe
  • C) The personal, cultural and religious beliefs of their patients
  • D) The patient’s condition only

Option D immediately sticks out as a less thoughtful and considered answer so students are most likely to pick it by default. I’ve noticed this as a particular problem when using MCQs for more ‘humanities-based’ questions. Whilst not impossible, writing good quality MCQs for these kinds of topics is definitely trickier, particularly finding good distractors. In this case it may be worth considering a 3-option format, for which there is a mounting level of evidence for their use, and having two good distractors is definitely favourable to having two good and one bad distractor.

Tip 9) Phrase your questions as simply as possible

You’re not aiming to test your students comprehension or trying to ‘catch them out’ with your test so don’t make your questions any more complicated than they need to be. In particular:
  • Avoid using double-negatives where possible
  • Be wary of adding in extraneous, irrelevant details to ‘throw off’ students (red-herrings)
  • Unless specifically testing a student’s technical vocabulary, don’t use complex words where simpler ones will do
You could argue that the students taking your tests should ‘read the question properly’ and such like, and to an extent this is true: if the student answers a question wrongly because they didn’t read the question then some of the responsibility for this has to lie with them, but ultimately it’s only going to make your test a less accurate, less relevant indicator of their actual knowledge so why not help them along where you can?

 

Tip 10) Avoid negative questions

Negative questions are things like ‘Which of the following is NOT true’, and the majority of testing experts recommend against using them. They can be tempting as they’re relatively easy to think up, but they can be confusing and, more importantly, are liable to be abused as a student may be able to find an incorrect answer without really knowing the correct answer, in which case you can’t confidently say whether they knew it or not.

Summary

Anyone can write an MCQ, but writing a good one that accurately tests a piece of knowledge and the student’s ability to apply it takes a bit more thought. Take time to ask yourself what it is you want to test with a particular question, and construct a question designed to do that.
We welcome you to try out Synap, our artificial intelligence tool for creating MCQ tests, practising them and sharing them with other people.We have over 200,000 questions written by our users and professional content writers on a huge range of topics. Sign up today and quiz your friends for free with synap, whether you are interested in learning about wrist anatomy, the kashmir earthquake orfrench er verbs , we have something for everyone!

References

Here are some more guides to writing great MCQs, we used them when we were starting Synap and refer back to them regularly!