Estimation Techniques Flashcards

An Agile team is estimating a large, unrefined backlog for the first time. The goal is to quickly group user stories by size to get a high-level forecast for release planning. Which estimation technique is most suitable for this scenario?

Answer: Affinity Estimating

Affinity Estimating is ideal for quickly sizing a large number of items. The team silently and collaboratively sorts backlog items into groups of similar relative size (e.g., Small, Medium, Large), making it much faster than estimating each item one by one, as is done in Planning Poker.

During a Planning Poker session, the team discusses a user story. When the cards are revealed, the estimates are wildly different, with one developer showing a '3', another a '13', and a third showing a '?'. What is the most appropriate next step?

Answer: Have the developers with the highest and lowest estimates explain their reasoning to foster discussion.

The core purpose of Planning Poker is to build a shared understanding through discussion. When estimates vary significantly, the developers with the outlier estimates (highest and lowest) should explain their rationale. This conversation uncovers different assumptions, hidden complexities, or misunderstandings about the work, leading to a more accurate, consensus-based estimate.

A primary benefit of using relative estimation techniques like Story Points or T-Shirt Sizing over absolute estimation in man-hours is that they:

Answer: Account for team-specific factors like complexity and uncertainty without being tied to a specific person or time duration.

Relative estimation focuses on comparing the effort of work items against each other rather than assigning specific time values. A story point or T-shirt size represents a combination of factors including the amount of work, complexity, and risk, which is unique to the team doing the work. This decouples the estimate from clock time, which can vary between individuals and over time, leading to more stable long-term forecasting through velocity.

Which of the following best describes Story Points?

Answer: A relative unit of measure for the effort required to implement a work item.

Story points are a relative measure of the effort needed to complete a user story. This 'effort' includes the complexity of the task, the amount of work involved, and any risk or uncertainty. They are intentionally abstract and not tied to specific hours or days to avoid the pitfalls of absolute time-based estimation.

A team is using T-Shirt Sizing (XS, S, M, L, XL) for high-level backlog estimation. How does this technique typically relate to more granular estimation methods like Story Points?

Answer: T-Shirt Sizing is often used for initial, coarse-grained estimation, which can later be converted to Story Points as items get closer to implementation.

T-Shirt Sizing is excellent for quick, high-level planning of large backlog items or early-stage roadmapping. As these larger items are broken down and refined, teams often convert the T-shirt sizes into the more granular Story Point scale (e.g., M = 8 points) for more precise sprint planning and velocity tracking.

An Agile team wants to estimate the effort for a small batch of prioritized user stories for the upcoming sprint. They value collaboration and want to ensure everyone's perspective is heard to avoid anchoring bias. Which technique is most appropriate?

Answer: Planning Poker

Planning Poker is specifically designed for collaborative, consensus-based estimation of a limited number of items. By having all team members reveal their estimates simultaneously, it prevents the opinion of one person from unduly influencing others (anchoring bias). The subsequent discussion about differing votes ensures all perspectives are considered.