My first and most valuable lesson I learned about market research and writing surveys was the "MECE principle." I first learned about it my sophomore year of college (about 15 years ago) sitting in my Principles of Marketing class. We were well-into our chapter on market research and we started discussing proper survey writing.
What is MECE in market research? MECE stands for Mutually Exclusive and Collectively Exhaustive. Mutually exclusive ensures that all survey response options offered in a question do not overlap one another and each is its own unique value. Collectively exhaustive ensures that you have covered the realm of all possible answers for a given question.
Here is an example of a survey question that is not mutually exclusive (and a rather common one I see a lot from inexperienced survey writers):
- Which of the following categories best describes your age? Select one.
- a) Under 18
- b) 18 to 25
- c) 25 to 35
- d) 35 to 45
- e) 45 or older
So what if you're taking this online survey and your age is 25, do you select B or C? If you are 45 years old, do you select D or E? Make sure your answer categories are exclusive from one another.
Here is an example of a survey question that is not collectively exhaustive:
- In a typical week, how many times do you use social media? Select one.
- Do not use social media
- About once every 2-3 days
- About once a day
- Several times a day or more
So what if you use social media once a week? Where is the option for weekly users? If you are asking a scaling or range question like the one above, it's important to make sure you have all categories covered from A to Z. If it is a choice-based question, always include an "other" to ensure you've exhausted all possible answers, like this:
- Which of the following social media websites is your favorite? Select one.
- Other (Please Specify)
This may seem like a basic survey writing tip but once you understand the MECE principle and abide by it, you'll be surprised by the amount of surveys you'll see that don't follow it. If you are working with a market research consultant or firm that doesn't follow this 101 rule, it should raise a red flag. Have questions about online survey writing or do you need to hire an online survey company to assist with your projects.