2.1 Exploratory Research
Usually researchers gain insights for a customer survey by conducting in-depth interviews with a few diverse customers until their answers become repetitive (Chapter 8). Their open-ended probing reveals the respondents' thoughts, feelings, motivations, perceptions, and other qualities. Then researchers summarize each respondent's answers, aggregate these profiles into a summary table, and select common answers as response options for survey questions.
Use open-ended questions in exploratory research so you can avoid them in survey research, thereby lowering your cost for coding and improving your response rate.