- Funnel
Use this question sequence when the interviewee knows the topic well and feels free to talk about it, or when the person wants to express strong feelings. This is the most common of all question sequences for all types of interviews. In this sequence, the interviewer begins with broad, open-ended questions and moves to more narrow, closed-ended questions. The interviewer may also begin with more general questions and gradually ask more specific questions.
- Inverted Funnel
This question sequence is effective when an interviewee needs help remembering something or to motivate an interviewee to talk. In this sequence, the interviewer begins with narrow, closed-ended questions and moves to more broad, open-ended questions. The interviewer may also begin with more specific questions and gradually ask more general questions.
- Diamond
The Diamond question sequence combines the Funnel and Inverted Funnel sequences. Use this sequence when dealing with topics interviewees may find painful or difficult and therefore are reluctant to discuss. Begin with specific, closed-ended questions about a situation similar to the interviewee's, then ask general, open-ended questions about the interview, and finally ask specific, closed-ended questions about the interviewee's particular circumstances.
- Tunnel
In this sequence, all questions have the same degree of openness. Also called the "string of beads" questions sequence, the Tunnel sequence allows for little probing and variation in question structure. It can be useful for simple, surface information interviews, but not for in-depth interviews.