Handling Estimation Disagreements

Handling Estimation Disagreements

Disagreements during estimation are healthy. They surface hidden assumptions, risks, and knowledge gaps. The goal is not to eliminate disagreement but to resolve it productively.

Why Estimates Diverge

1. Different assumptions -- One person assumes the existing API works; another knows it has a bug that needs fixing first.
2. Different experience -- A senior developer has solved this type of problem before and sees it as simple. A newer developer sees many unknowns.
3. Scope ambiguity -- The story is vague enough that people imagine different implementations.
4. Risk perception -- One person sees a straightforward task; another sees a fragile dependency that could blow up.

Resolution Techniques

The Two-Minute Rule

After the reveal, give the highest and lowest estimator exactly 2 minutes each to explain their reasoning. No interruptions. Then re-vote.

Clarifying Questions

Often, a single question resolves the gap:

• "Are we assuming the API already exists?"
• "Does this include mobile or just web?"
• "Is error handling in scope?"

Default to Higher

If the team cannot converge after two rounds, take the higher estimate. Under-estimation is more damaging than over-estimation because it leads to broken sprint commitments.

Split the Story

When a wide spread (e.g., 3 vs 13) persists, the story is probably too large or too vague. Split it into smaller pieces and estimate each.

What NOT to Do

• Do not average -- Planning poker is about consensus, not arithmetic. A 3-and-13 average of 8 satisfies nobody and reflects nobody's understanding.
• Do not override -- If the team says 8 and the tech lead says 3, the team's estimate stands. Overriding destroys trust.
• Do not shame -- "That's a ridiculous estimate" shuts down honest assessment. Every estimate has a reason; find it.

Facilitation Tips

• Track how often the team converges on the first vote vs needing re-votes. If re-votes are rare, stories may not be getting enough scrutiny.
• If the same two people always disagree, pair them on a story. They will calibrate over time.