How to interview an expert so real knowledge comes out
You cannot ask an expert to 'tell you what he knows' — expertise is organized for use, not for recital, and the owner cannot see his own tacit layer. Elicitation works indirectly: prepare from his real cases, ask him to walk through specific decisions, probe the deviations and exceptions, capture the reasoning verbatim, and return in layers — the second session over the same ground reliably outyields the first.
Before you start
Prerequisites: a willing expert (elicitation is done with, never to), preparation time per session (unprepared interviews produce anecdotes), and a recording arrangement the expert controls. One more mindset item: the interviewer's job is curiosity, not verification — experts open up to genuine 'how does that work?' and close down to being tested.
The steps
Step 1 — Prepare from artifacts, not imagination
Before each session, study real material: recent decisions, project files, incident reports, the questions colleagues actually ask him. Build a question list anchored in specifics — 'the Meyer quote from March' beats 'your quoting process'.
Pitfall: Generic question lists ('describe your role'). They produce the polished version the expert has told at birthdays for years — organized memory, not working knowledge.
Step 2 — Ask for cases, not opinions
The core move: 'walk me through the last time you…'. Concrete episodes force the real reasoning to run again, in order, with the details that opinions summarize away. Follow the case chronologically and ask what he saw, thought and did at each point.
Pitfall: Asking 'how do you usually…'. 'Usually' invites the espoused theory; the last actual case reveals the theory-in-use — they differ, and the difference is the knowledge.
Step 3 — Probe the forks and deviations
At every decision point ask: what else could you have done? What would have made you choose differently? When did this rule not apply? Exceptions are where expertise concentrates — the standard path is usually documented; the deviations never are.
Pitfall: Accepting the first answer. Experts compress; the follow-up ('what told you that?') decompresses. Three whys deep is normal, not rude.
Step 4 — Capture verbatim, structure later
Record the reasoning as spoken — the hedges, the rules of thumb, the 'it depends' with its dependencies. Structuring during the conversation loses material; the expert's own words carry information a summary strips (and they preserve his reasoning style).
Pitfall: Taking clean notes live. Clean notes are premature summaries — the polishing is where tacit detail dies.
Step 5 — Return in layers
Space sessions a week or more apart and revisit domains: the first pass gets the accessible layer, and the expert's memory keeps working between sessions — the second pass reliably surfaces what the first couldn't reach. Bring back what he said and ask what's missing or wrong.
Pitfall: The single-pass schedule. One session per topic feels efficient and forfeits the deepest material — depth is a function of return visits, not session length.
Step 6 — Verify through use
Test the captured knowledge against real questions from the team, with the expert reviewing the answers. Corrections at this stage are cheap and — usefully — trigger more elicitation: 'no, that's wrong because…' is often the best session opener there is.
Pitfall: Verifying by asking 'is this complete?'. He cannot know — the same blindness that made elicitation necessary. Only use reveals the gaps.
How MentX compresses this
MentX is a personality-aware knowledge base: it captures the knowledge of a company's key person — from meetings and a guided intake track — into a living, temporal knowledge graph with full source attribution. This method is MentX's Deepen track, run by us as a service: prepared, case-based, layered sessions — personality-aware, so the questioning follows how this expert thinks. Connect adds what no interview reaches (the daily reasoning in his real meetings), and every captured statement lands in the temporal knowledge graph with full source attribution, verbatim sources included. The expert's veto rights close the loop of step 6.
Checklist
- Session prep anchored in real artifacts and colleague questions
- Case walk-throughs, chronological, specific
- Forks, exceptions and 'when not' probed three whys deep
- Verbatim capture; structuring done after, not during
- Domains revisited in spaced layers
- Answers verified through real team use, with the expert reviewing
