Semi-structured interview, structured interview, unstructured ... (Qualitative interviews #1)

Qualitative interviews come in three core formats—structured, semi-structured, and unstructured—and the most important choice isn’t the label from the literature. The priority is designing an interview that reliably elicits answers to the study’s research questions.

Structured interviews (often called survey interviews) run on a tightly fixed interview guide with predetermined focus and response categories. Questions are designed to produce comparable, easy-to-code answers. A typical example is asking participants how much they like a specific food (like curry), with response options such as “really like it” or “don’t like it at all.” The structure keeps participants on the intended topics and channels their responses into categories that can be analyzed later.

Semi-structured interviews keep a general structure but leave room for participants to generate new insights. The guide provides broad topics and prompts, while the interviewer encourages elaboration. This format is especially useful when the researcher has a sense of what to cover but cannot fully predict what participants will say. In contrast, unstructured interviews are highly open-ended and often resemble real-life conversation. They may include little or no interview guide and are common in ethnographic work, where the goal is to understand how people talk about beliefs, practices, and behaviors within a cultural or organizational setting.

A related distinction matters when group settings enter the picture: a group interview involves interviewing an entire group by asking questions to multiple members, and it is not the same as a focus group interview. Some authors treat them as interchangeable, but the distinction is important for choosing the right method.

The central practical message is to avoid getting stuck on method names before the study begins. Instead, researchers should first clarify what they need to learn, who they will talk to, and what relationship or context will shape the interaction. A clear purpose and a workable plan for eliciting responses matter more than selecting a specific interview type upfront.

That principle is illustrated through a personal research example on migrant identity in Scotland. When the interviewer used very specific prompts—such as asking participants to remember particular experiences from years earlier—participants often did not recall the targeted details during the interview. After the interview, however, they shared the stories the researcher had been seeking. The mismatch suggested that the interview setting and the pressure of answering narrowly framed questions reduced recall.

To address this, the researcher shifted toward a narrative interview approach: using a general guide while giving participants more freedom to speak. Even when participants went off-topic, the unplanned material sometimes contained the most relevant insights. The takeaway is that interview design should be iterative—guided by pilot observations, intuition, and what actually helps participants produce meaningful accounts.

Overall, the method choice should serve the research questions. Once the researcher understands what elicits strong responses in context, the interview format becomes clearer—whether structured, semi-structured, unstructured, or something else within that spectrum.