If nothing was unclear or difficult, say so. Skip questions about steps you did not experience; use not applicable where appropriate.

Which location was difficult to find?
Where did you expect a direction sign?
What label would help?

Author notes / illustrative keys where applicable:
1. Use this answer to locate the part of the experience that needs explanation. The example issue to investigate is: attendees confuse session rooms with similar names.
2. An expected sign location identifies a decision point where directions were unavailable. Place checked destination guidance at that point; the respondent's route may differ from other entrances or available access arrangements.
3. Turn the requested improvement into a testable next step. One illustrative action is: use consistent room labels at key junctions.