Multiple select question types is one of the most commonly used items in survey questionnaires. But like any question type, there are several online survey best practices that go along with the multiple select (or Select all that apply) question type.
Always include a None option as an exclusive choice
Take the example survey question from a consumer opinion survey below. Sample Consumer Survey Question Not everyone has read any or all of the Twilight saga nor has everyone has seen the movies. If this question was critical to your data set, and there is no None option, how do people respond? There is nothing more frustrating to a survey respondent than to get to a question and not be able to answer it - particularly if it's required. If you don't listen to this best practice, you'll find yourself with ambiguous data. Was a skipped question really skipped, or is no answer their answer?
Randomize the response order
This survey best practice only applies if your answer options don't have a natural order to them. Taking the same example question from above, we can tell there's a natural order - the order the books were released. However, if we has this next sample survey question from a different consumer questionnaire, we'd want to randomize the order. Sample Consumer Survey Question When you have long lists like this one, respondents will often pick the first few responses that apply to them, feel they've sufficiently answered the question and move on to the next question. By randomizing the response options, you remove this bias from your data set.
Don't use choices that overlap in meaning
By providing multiple answers that overlap, the respondent might be inconsistent with their choices. How does that effect your survey results?
Remind respondents to select all that apply
Even though it's standard that multiple select questions show up as check boxes, where as single select as radio buttons, the survey respondent still needs a reminder. It's simple enough to do, and if you notice, both examples so far explicitly remind respondents they can select multiple answers.
Avoid list boxes or drop downs for choices
While almost every online survey tool I've come across has this question type as an option, it's best practice to use the check box option. Using list boxes or drop downs can be confusing to the survey respondent, and you may not get accurate data as a result. Sample Consumer Survey Question My final survey best practice for multiple select question types is consider replacing this one question with a Yes/No Matrix question. Sometimes this question type can be more appropriate than the multiple select option. Don't forget with this question type, you can limit the number of responses that are chosen (as well as set a minimum). For example, you may be conducting a course evaluation survey and want to know which books students found most meaningful. Obviously everyone will not like the same books, but it's not helpful if they select all the books. Course Evaluation Survey Template Question I've said it once, and I'm sure I'll say it many times over, writing survey questions is not as simple as we might think at first glance. There are lots of online survey pitfalls and best practices to keep in mind. By Sherrie Mersdorf