How to design questions that ask participants to choose one item from a set of options 🔗

When you ask a question that involves choosing just one category from a set of categories, it is important to make sure the categories are MECE ("mutually exclusive and collectively exhaustive"). That is, each study participant should have exactly one option that applies to them.

In some cases, you won't be able to list all possible options. In that case, it is advisable to avoid creating categories that overlap with each other and then to add an "Other" option. You may also need an option saying "I don't remember" or "I don't know" in cases where people really may not know the answer.

Good categorical question examples 🔗

Here are some good examples of mutually exclusive and collectively exhaustive categorical questions:

*question: What is your relationship status?
	Never married
	Currently married

*question: What was the most recent reason you went to a doctor's office?
	*save: lastReasonForDoctorVisit
	A physical injury to my body
	A virus or bacterial infection
	A mental health-related reason
	Hypertension (high blood pressure)
	Hypercholesterolemia (high cholesterol)
	A general check-up
	I don't know or I don't remember

Bad categorical question example 🔗

And here is a bad example of categories that aren't mutually exclusive or collectively exhaustive:

*question: What do you like to do for fun?
	See friends

In the example above, the answer options are not mutually exclusive, since you can like more than one; and they are not collectively exhaustive, since there are things you may like to do for fun that are not on here. They also are in a fixed order, whereas the order should be randomized.