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.