Interview Guide

Origin & evolution

The interview guide is the defining artefact of the semi-structured interview, a method that grew out of mid-twentieth-century sociology and the focused-interview work of Robert Merton in the 1950s. It sits between two extremes: the fully structured interview, where every participant🙋ParticipantUser ResearchA person participating in researchView reference → hears identical wording in identical order, and the unstructured interview, which is closer to a guided conversation with no fixed agenda. The guide gives a researcher a consistent spine of topics while leaving room to follow what a participant actually says.

User research inherited and refined one technique in particular. The Nielsen Norman Group's funnel technique structures each line of questioning to move from broad and open to narrow and closed. You open with a wide question that lets the participant define what matters, then zoom in on the specifics they raised. NN/g notes that a typical user-interview guide holds five to eight open-ended questions, each with follow-up probes, rather than a long list of closed items.

The persistent failure mode is the leading question, which smuggles the answer into the wording ("How much did you love the new dashboard🎛️DashboardData & AnalyticsAn analytics dashboardView reference →?"). A good guide is drafted to keep questions neutral and open, so the participant supplies the content. That is the line between a guide and a script: a script dictates exact phrasing for reproducibility; a guide names the territory and trusts the interviewer to adapt.

A related failure mode that Fitzpatrick identifies in *The Mom Test* is the opinion or hypothetical question — asking "Would you use this?" or "Do you think you'd pay for X?" invites polite, speculative answers rather than evidence🔎EvidenceValidationData supporting or refuting a hypothesisView reference →. His prescription is to ask about concrete past behaviour instead: "Tell me about the last time you did X" forces a participant to recall a specific event, which tends to surface what actually happened rather than what they imagine they might do. A well-drafted interview guide applies both disciplines: it strips leading wording and replaces hypothesis🧪HypothesisValidationA testable belief about a solutionView reference → questions with behaviour-anchored prompts.

How it works in practice

A researcher studying how teams adopt a new analytics tool writes a guide with six topic areas. The onboarding section opens wide: "Walk me through the last time you set up a new report." Only after the participant tells that story does the guide narrow to probes about where they got stuck and what they did next. A drafted-out leading question, "Was the setup confusing?", is struck during review and replaced with "How did the setup go?".

Across eight sessions the spine holds, so every transcript covers onboarding, daily use, and sharing. Within each session the funnel⬇️FunnelGrowthA conversion funnel tracking user progressionView reference → lets one participant spend ten minutes on a sharing problem the team had not anticipated. The guide delivered comparability across interviews and the freedom to chase the unexpected inside each one.

Portigal's *Interviewing Users* treats the guide as a scaffold for interviewer judgment rather than a checklist to execute. His argument is that the quality of what a participant reveals depends as much on how an interviewer builds rapport, handles silence, and follows unexpected threads as on how the questions are worded — the guide sets the territory, but skilled in-session adaptation determines whether a participant reaches the level of candour where genuinely useful material surfaces.

Interview Guide vs. its neighbours

• Research question❓Research QuestionUser ResearchA question guiding a research studyView reference → is what the study is trying to learn; the interview guide is the instrument that elicits answers to it. One research question usually maps to several guide questions, and a guide question phrased as the research question itself is too abstract for a participant to answer.
• Research study🧑‍🔬Research StudyUser ResearchA planned research activityView reference → is the whole investigation🔍InvestigationEngineeringAn investigation into an issue or incidentView reference →, including recruitment, sessions, and analysis. The guide is one document the study follows during data collection. Swapping the guide mid-study quietly breaks comparability across participants.
• Participant is the person answering. The guide is written before anyone is recruited, then adapts live to each participant's responses through its follow-up probes. The same guide produces different conversations with different participants, which is the method working as intended.

In the graph

In the Unified Product Graph, an interview guide lives in the user-research region as the protocol a study follows during qualitative sessions. The research_study_follows_interview_guideResearch StudyfollowsInterview Guidehierarchy edge binds the guide to its study, which keeps the instrument attached to the investigation that used it. That matters for traceability: when an insight🔦InsightUser ResearchA synthesised finding from researchView reference → is questioned later, a team can walk from the study to the exact guide, see how a topic was phrased, and judge whether the finding came from a neutral prompt or a leading one.