Writing multiple-choice questions is hard. There are number of common traps educators fall into when developing a multiple-choice question that undermines their capacity to properly assess student knowledge. Educators often miss the opportunity to leverage multiple-choice quizzes as a learning opportunity for students as well.
Here's a quick-guide on some dos and don'ts for writing effective multiple-choice questions. A 2-minute video follows that presents a worked example.
There's a myth perpetuated by many guides to writing multiple-choice questions that you should use four or even five answer options. The logic being the more options you provide, the less likely students will simply guess the right answer. Sounds reasonable, right?
It's rubbish* and worse yet it actually undermines your capacity to properly assess a student's knowledge.
A first rule-of-thumb is to use only three answer options per question, inclusive of the correct answer. Here's why:
1.) For most types of questions, it is difficult to come up with sensible distractors (i.e., wrong answers). Writing one or two plausible (but otherwise wrong) answers is obtainable. Yet, even here it can be hard not to write answers that most students would easily identify as being wrong. The result is students can simply rule out the silly alternatives to identify the right answer. This means you're testing a student's capacity to spot implausible answers, and potentially without needing any credible understanding of the question, rather than testing a student's understanding of the topic.
2.) The more answer options you provide, and assuming you can write those as credible wrong answers (see point 1 above), the greater the cognitive load you're forcing onto a student. What does this mean? First, a student must read, understand and retain the information conveyed by a question. Second, a student must then read, understand and retain the information PLUS its relevance to the question for each answer option provided. The more options you provide, the more you're actually testing a student's capacity to retain information rather than establish its relevance to the question. This problem is especially acute when abstract answers like "A and C" or "all of the above" or "none of the above" are used as options. Cognitive overload also varies by student, with neurodiverse students or students who's first language is not English being even more susceptible.
On a related point, true or false multiple-choice questions, when carefully written, can be just as effective at testing a student's knowledge as a question with three answer options. Ideally you should pepper your quiz with a variety of True/False and 3-answer option questions.
A second rule-of-thumb, again for reducing cognitive overload, is to pay careful attention to both the length and complexity of language used for both questions and answers. Review your question to ensure it provides all the necessary information for a student, and in the fewest words and in the simplest language. Your answer options should be similarly simplified as much as possible.
A third rule-of-thumb, whenever possible, is to provide feedback to a student on why they did or did not get a question right. It isn't simply enough to provide the correct answer, rather you also need to clarify why that answer is correct and why an alternative option selected was not correct. This is because a student who gets a question right might not fully understand why it's the correct answer. Conversely, a student who doesn't get a question right might not understand why it's the wrong answer. So, by providing this type of complete feedback, the multiple-choice question now becomes a learning opportunity as well.
On a last point, don't underestimate the time and effort needed to properly write and construct a multiple-choice question. If you think using an assessment based on a multiple-choice quiz is an 'easy out' because it's quick to write and mark, you're right on only one of those. If you have written multiple-choice questions and still think it's easy, chances are you've fallen into the pitfalls described above and might need to review your existing quizzes...
The video below illustrates a worked example of these dos and don'ts**.
*Don’t just take my word for it, follow the hard data trail. The studies below are just the tip of a very large evidence iceberg that sinks the traditional Titanic view of putative ‘best practice’:
Rodriquez, M. C. (2005). Three options are optimal for multiple-choice items: a meta-analysis of 80 years of research. Educational Measurement: Issues and Practice 24: 3-13.
Kilgour, J. M. and Tayyaba, S. (2016). An investigation into the optimal number of distractors in single-best answer exams. Advances in Health Science Education 21: 571-585.
Loudon, C. and Macias-Munoz, A. (2018). Item statistics derived from three-option versions of multiple-choice questions are usually as robust as four- or five-option versions: implications for exam design. Advances in Physiologiy Education 42:565-575.
Brabec, J. A., Pan, S. C., Bjork, E. J. and Bjork, R. A. (2021). True-false testing on trial: guilty as charged or falsely accused? Educational Psychology Review 33:667-692.
Al-lawama, M. and Kumwenda, B. (2023). Decreasing the options’ number in multiple choice questions in the assessment of senior medical students and its effect on exam psychometrics and distractors’ function. BMC Medical Education 23:212
Sridharan, K. and Sivaramakrishnan, G. (2025). Less is more? A systematic review and network meta-analysis on MCQ option numbers. BMC Medical Education 25: 1430.
**Here are a couple of sensible, evidence-based and theory-based practical guides:
Gierl, M. J., Bulut, O., Guo, Q. and Zhang, X. (2017) Developing, analysing, and using distractors for multiple-choice tests in education: a comprehensive review. Review of Educational Research 87:1082-1116.
Gottlieb, M., Bailitz, J. Fix, M., Shappell, E. and Wagner, M. J. (2023). Educator’s blueprint: a how-to guide for developing high-quality multiple-choice questions. AEM Education and Training 7:e10836.