What estimation technique is an agile team using when collectively estimating the relative size of its stories using story points?

Planning Poker is a consensus-based estimation technique commonly used by agile teams. Team members use numbered cards (often following a modified Fibonacci sequence) to privately vote on the size of a user story. After revealing their cards simultaneously, the team discusses any significant variances and re-votes until a consensus on the story point value is reached. This method combines expert opinion, analogy, and disaggregation to estimate relative size, fostering collaboration and shared understanding of the work.

A. Parametric estimation uses statistical models and historical data to calculate estimates, which is different from the collaborative, relative sizing of Planning Poker.
B. One-to-one comparison is a general concept, not a specific, named agile estimation technique like Planning Poker.
C. Affinity estimating is a technique used to quickly group and size a large number of user stories, but Planning Poker is the specific gamified, consensus-driven method described.

1. Project Management Institute. (2017). Agile Practice Guide. Section 5.2.3.3, Common Agile Estimating Techniques, p. 61. "Planning Poker... This technique blends consensus with individual expert opinion... to arrive at a shared, agreed-upon estimate."

2. Haugen, N. C. (2006). An Empirical Study of Using Planning Poker for User Story Estimation. Paper presented at AGILE 2006 Conference. This paper details the process and benefits of Planning Poker for collective, relative estimation. DOI: 10.1109/AGILE.2006.33.

3. Mahnič, V., & Hovelja, T. (2012). On using planning poker for estimating user stories. Journal of Systems and Software, 85(9), 2086-2095. This academic article analyzes Planning Poker as a method for collective estimation. https://doi.org/10.1016/j.jss.2012.04.005