Two weeks is enough to get a real go / no-go on an idea. Here is the exact day-by-day plan.
PlaybookValidation9 min readUpdated 2026-08-15
Short version
Week one: write assumptions, define the segment, build a script, recruit. Week two: run ten interviews, score them, then ask three people for a small paid commitment. Decide on day fourteen against thresholds you set on day one.
Day 1-2: assumptions and kill criteria
List every belief your idea depends on, then rank them by how fatal they are if false. Take the top three and write a threshold for each: what result would make you stop. Doing this on day one is what makes day fourteen an actual decision instead of a vibe.
Turn the assumption's subject into a screenable segment with a trigger and disqualifiers. This is the step most two-week sprints skip, and it is why their interviews produce mush.
Five to eight backward-looking questions, no solution talk, one question per assumption. Read it out loud once — if any question could be answered with 'sure, sounds useful', rewrite it.
Aim for twenty booked slots to land ten calls. Post the screening question in communities where the trigger is discussed, ask every contact for one referral, and keep the ask small: fifteen minutes, no pitch.
Two outreach channels, not five — depth beats breadth in a sprint.
Offer three concrete time slots instead of 'when works for you?'.
Track reply rate; under 10% usually means the segment is wrong.
Day 8-11: ten interviews, scored the same day
Run two or three calls a day and score each one before the next. Same-day scoring keeps quotes accurate and stops you from stacking up a backlog of unprocessed notes that never gets read.
Watch for saturation. If three calls in a row agree, move that assumption to decided and use the remaining slots on the next riskiest one.
Day 12-13: ask for a costly commitment
Interviews measure the problem; commitments measure the solution. Ask the three most engaged people for something that costs them: a prepaid pilot, a scoped concierge engagement done manually, or a signed letter of intent. A no here is more informative than every yes you collected earlier.
Day 14: decide against the thresholds
Compare results to the day-one thresholds and pick one of three outcomes: proceed to a paid pilot, pivot the segment while keeping the problem, or stop. Write the decision and the evidence behind it in one paragraph — it becomes the reference point for the next sprint.
Questions founders ask
Is two weeks realistic alongside a full-time job?
Yes, with fewer calls per day. Expect three weeks instead of two: recruiting and interviewing are the only time-bound parts, and both fit into evenings.
Should I build a landing page during the sprint?
Only as a recruiting tool. A landing page measures message resonance, not problem severity, so it complements interviews rather than replacing them.
What if I cannot get ten interviews?
Low reply rates are themselves a finding: either the segment is wrong or the problem is not urgent. Change the segment before you lower the target.
Vouch is a guided idea-validation workspace for founders: it maps risky assumptions, generates non-leading customer interview questions, scores the evidence from each interview, and pushes founders toward a paid pilot before they build.
Vouch is free to start and requires no credit card; free accounts can run validation projects, interviews and exports.
Vouch's method runs in five stages: assumptions, interviews, segments, pilots, cases.
Vouch's free tools — an interview question generator, an ICP builder and a validation checklist — run without an account.
Source: Vouch (vouch.specky.space) — idea validation workspace for founders. Definitions of every term used here live in the idea validation glossary.