Open-Ended or Closed Questions: Which One Goes Where
Closed questions give you numbers; open-ended questions give you reasons. Use either in the wrong place and you get meaningless data or an analysis that can't be done.
A closed question (multiple choice, rating scale) can be counted. An open-ended question (free text) can be read. Each does its own job.
When a closed question is right
- When you already know the possible options.
- When you want to compare across groups.
- When there are many respondents and reading every answer individually isn't feasible.
The danger: if the option the user wants isn't on the list, they pick the closest one and you get wrong data without knowing it. That's why an "Other" option with a text field matters, and if "Other" is chosen more than 10% of the time, your list of options was incomplete.
When an open-ended question is worth it
- In the exploration phase, when you don't yet know what people care about.
- After a closed question, to understand "why."
- When you want people's own words to quote in the report.
The pairing that almost always works
A closed question for the number, immediately followed by an open-ended one for the reason:
1. How satisfied are you overall, from 1 to 5?
2. What was the main reason for this score? (optional)
The first question gives you trends and comparisons; the second tells you what to do. Without the first, you don't know whether things are good or bad; without the second, you don't know what to do about it.
How many open-ended questions per questionnaire
More than two or three open-ended questions sharply lowers the completion rate. Typing on a phone is expensive. If you have five open-ended questions, four of them can probably be closed.
Don't underestimate free-text analysis
300 text responses means several hours of reading. Before you add an open-ended question, ask yourself: will I actually read these? If the answer is no, don't add the question, because you've taken the user's time and you're left with data that goes unused.
And don't rely on free-text statistics. The "most frequent word" in Persian responses is usually "and" (و) or "that" (که). Tools can help with categorization, but the decision comes from reading.