Time Discipline
The 1/6 → 1/3 → 2/3 time allocation. Warm-up, Build, Peak, is not rigid dogma. It's a framework for conscious time management that separates skilled interviewers from novices.
The Standard Model
For a 45-minute interview:
- Warm-up: ~7 minutes
- Build: ~15 minutes
- Peak: ~23 minutes
The Peak phase being twice as long as everything else combined isn't a coincidence. Shallow coverage of many topics is easy. Deep exploration of a few topics produces evidence.
Adaptive Management
The "trail" metaphor is intentional. While there's a planned route, experienced hikers know when to detour.
If a participant reveals an unexpected but relevant problem during Build, adjust the Peak phase to explore it. But the adjustment must be conscious:
- "I'm spending 5 minutes on this. That means I'm cutting questions about topic Y or extending the interview."
- Not: "Oh, that's interesting" (drifts for 15 minutes, loses the thread).
The Internal Clock
Experienced interviewers develop an internal rhythm: by minute 8, I'm in Build. By minute 18, I'm entering Peak. By minute 38, I've covered my two core hypothesis areas.
When this rhythm breaks:
- Still in Warm-up at minute 12? The conversation isn't focused enough. Tighten.
- Participant is concise and unreflective? Extend Build with more memory-prompting questions.
- Participant is voluble but tangential? Gently steer back toward relevant territory.