Unstructured interview
An unstructured interview is a qualitative interview with no fixed questions or order: the interviewer starts from a broad topic and lets the conversation develop from the participant's answers, much like a guided conversation.
How it works
The interviewer may prepare only an opening question and a list of themes. From there, each question grows out of the last answer. The approach gives participants the most freedom to raise what matters to them, which makes it useful early in exploratory research, for sensitive topics and for life-history work.
The freedom has costs. Interviews are hard to compare, since each covers different ground; they depend heavily on the interviewer's skill; and they take longer to analyze. Most applied research therefore uses semi-structured interviews, keeping unstructured ones for the first stage of a study or for topics where any structure would steer participants.
A worked example
A nonprofit exploring why young adults stop volunteering opens 8 unstructured interviews with one question: "Tell me about the last time you volunteered." Themes nobody had listed emerge, such as feeling unqualified, and they shape the semi-structured guide used in the next 30 interviews.
Related
Automate this in Pulse
A Pulse brief with a single broad area comes closest to an unstructured interview, since the moderator opens on it and builds the rest of the conversation from follow-ups.