You're merrily filling out a survey for some company when you come to a question you just can't answer. Maybe the question is asking about something you don't have any experience with, or maybe the question doesn't make sense (not every survey is well-written). So you skip the question and click the "Next" or "Done" button.
Only to be sent back to the same page with angry red highlighting on the skipped question and a stern warning: "You must answer this question to continue."
At this point you can (a) abandon the survey, or (b) make up a fake answer. Honestly answering the question isn't an option.
This is why mandatory survey questions are evil:
- Mandatory survey questions don't respect the fact that the customer is doing you a favor. The first rule of conducting customer surveys should always be that the customer's feedback is a gift, and should be treated as such. If a customer doesn't want to answer a question, you need to deal with that fact and not act like you're entitled to an answer.
- There is no situation which actually requires using mandatory survey questions. A good survey designer and a well-designed process can easily find better ways to do the things mandatory questions are there for. Skip logic? Design a path for "no answer" responses. Blank surveys? Filter them out in analysis instead of rejecting what feedback there might be. Giving incentives? If someone turns in a blank survey send them an "Oops, you forgot to fill out the survey" response.
- Skipped survey questions are a problem of survey design, not the customer's intent. Mandatory questions treat skipped questions as though the problem is the customer doesn't want to do the survey. But you already know the customer wants to do the survey because he's doing the survey. If you have skipped questions, the problem is the survey is poorly designed. Chances are it's too long, or you're asking questions which don't make sense to the customer. In the real world, well-designed surveys have very few skipped questions: we expect just a couple percent of people to skip any given closed-ended survey question.
- Mandatory survey questions tell the customer you don't care about his feedback. Forcing the customer to answer a survey question he doesn't want to (or can't) answer says that you would rather get no feedback at all from the customer than a survey with a single box unticked. That hardly seems like the message you want to give to someone who is, after all, taking the time to help you improve.
If you have a survey with any required questions, just make them all optional. You will get better feedback, your response rate will go up, and you will sleep better at night knowing that you aren't aligned with the forces of darkness.