One of the first pointers I remember learning in marketing research class in college regarding survey writing was making survey questions mutually exclusive and collectively exhaustive. Remembering this simple tip still helps our team make surveys precise and trouble-free for our survey respondents in Central New York and all across the country. Let me take some time to explain what each of the two key standards indicate.
1) Mutually Exclusive – the first measure ensures that each individual answer given in a single or multiple response survey question cannot be true at the same time. Survey writers need to double-check their listed responses so that each answer is exclusive to another. This is a common mistake among inexperienced survey writers (and even experienced ones).
Incorrect Example: See below. Examining the answers a through g, you’ll see that they overlap and are not mutually exclusive. If a survey respondent is 35, which answer do they select – c or d? This is a common mistake on any type of aided range question – income level, length of time, date ranges, etc.
Correct Example: See below. Age ranges are mutually exclusive. No one answer can be true for more than one of the answer categories.
2) Collectively Exhaustive – the second measure ensures that all answers given for the question cover the entire realm of possible answers. Survey writers listing answers in an aided single or multiple response question need to make sure that all potential answers to the particular question are listed for the respondent. And remember, when in doubt, use “other!”
Incorrect Example: See below. Examining the answers, you’ll see that not all potential answers are covered in the given list. What if a respondent wants to receive a coupon through email? What if a respondent wants to receive a coupon when they visit the store? This is a common mistake for any aided single or multiple response question.
Correct example: See below. This corrected question now lists email and also more importantly provides an option for the respondent to write-in an other. This is a good way for survey writers to ensure they are covering all the proverbial bases of answers. If you have multiple newspapers or magazines in your region that reach your target market, you may want to list of each specific newspaper or magazine to better target your coupons. You could also ask the respondent to specify which newspaper or magazine.
Remembering the phrase mutually exclusive and collectively exhaustive goes a long way for survey writers. Abiding by this tip and using it in future surveys will help you create a more complete and accurate script to make certain you are gaining actionable information for marketing research and strategy development for your business.
[…] bias and other problematic errors. Also, like other questions in market research, they should be mutually exclusive and collectively exhaustive by not doubling up/overlapping categories and by covering all answers. Avoiding these problems […]
[…] us in the bunker to cringe when we see hastily written surveys. Such mistakes (to name a few) as: mutually exclusive and collectively exhaustive and scaling mistakes and what not to […]
[…] Note others. Many times with bar graphs or any type of graph that involves coding in market research, you have to use the ever-popular “other” category. If the % of your “other” category is high, say 10%+, you should reference what constitutes in that “other” category in a footnote on the page. It ensures you’ve covered all response categories and that your graph is exhaustive. […]
George,
I agree that thinking MECE is a fundamental part of developing effective surveys.
Another fundamental part, complementing the MECE approach, is to ensure that the breakdown you’re using is also insightful.
So, going back to your example of age groups, you might find that breaking the population in groups of 10-year increments isn’t optimal. If, for instance, most of your respondents are between ages 25 and 44, you might decide that you should cut that segment in 4 (or more) not just 2.
That’s a great point Arnaud. We see that a lot with our school district surveys in which many of the parents of school aged children fall in that 25-44 range. So splitting those groups up further, allows us more flexibility on analysis.
Another option we’ve found that works is simply asking for birth year. It seems less intrusive to the respondent (than straight out age) and allows us to slice the data how we see fit.
[…] This is more commonly referred to as collectively exhaustive in market research terms, part of the MECE principle. The results of not taking the time to ensure your selected responses question covers the entire […]
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[…] George, K. (2018, August 16). Mutually Exclusive & Coll. Exhaustive. Retrieved from Survey Tips. Researching & Marketing Strategies: https://rmsresults.com/2010/04/27/mutually-exclusi… […]
[…] George, K. (2018, August 16). Mutually Exclusive & Coll. Exhaustive. Retrieved from Survey Tips. Researching & Marketing Strategies: https://rmsresults.com/2010/04/27/mutually-exclusi… […]
[…] George, K. (2018, August 16). Mutually Exclusive & Coll. Exhaustive. Retrieved from Survey Tips. Researching & Marketing Strategies: https://rmsresults.com/2010/04/27/mutually-exclusi… […]