The correct answer is D – Estimating the relative size of stories by using story points.

Planning poker is a consensus-based estimation technique used in Agile to assign relative size (often using story points) to product backlog items. Each team member selects a card to indicate their estimate, and the group discusses discrepancies to reach agreement.

From the PMI Agile Practice Guide:

“Planning poker is a consensus-based estimation technique that helps teams estimate the size of user stories using story points. It supports collaboration and shared understanding.”

(PMI Agile Practice Guide, Section 5.3 – Estimation Techniques)

Mike Griffiths writes:

“Planning poker helps teams perform relative sizing using a modified Fibonacci sequence. The goal is not precision, but shared understanding and relative complexity comparison.”

(Mike Griffiths, PMI-ACP Exam Prep Book, Chapter 5 – Adaptive Planning)

Why other options are incorrect:

A describes analogy-based estimation, not planning poker.

B refers to “bucket system” estimation, a separate technique.

C refers to dot voting, which is a prioritization—not estimation—tool.

Answer: D

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