A programme manager building a release plan tells the Scrum Team that no Product Backlog item may be selected for a Sprint until it carries a story-point estimate agreed in a recurring refinement session, "because that is how Scrum sizes work". What is true?

Professional Scrum Master I, objective 3. Managing products with agility easy

Machine-checked — no person has signed for it. This question was read against the source cited below by an automated pass, which found no contradiction. That is a weaker claim than it sounds: the same kind of process wrote the question, so it can confirm its own mistake.

Treat it as a good draft rather than as settled fact, and read the source below before you rely on it. It is not used in mock exams here — only questions a person has signed for are.

The options

Correct Scrum asks only that an item be refined enough to be Done by the Scrum Team within one Sprint for it to be deemed ready for selection; it prescribes no estimation unit and no such meeting

Correct. Readiness in Scrum is a statement about size relative to a Sprint, not about a number written on a card. How a team expresses size, and where it does the refining, is left to the team.

Not correct Story points are Scrum's sizing unit, so an item without one cannot be selected

Wrong, and it is the folklore this question exists for. Refinement adds details such as a description, order and size, but Scrum names no unit at all — story points are one popular practice layered on top of the framework.

Not correct The Product Owner must supply the estimates, since ordering the Product Backlog depends on knowing the sizes

Wrong. The Developers who will be doing the work are responsible for the sizing; the Product Owner may influence them by helping them understand and select trade-offs, which is a different act from handing them numbers.

Not correct Sizing is unnecessary in Scrum, because the Sprint Goal replaces any need to know how big items are

Wrong, and it overcorrects. Refinement explicitly adds size among the details it adds, and a forecast made in ignorance of size is not a forecast. What Scrum leaves open is the technique, not the need.

Why

Refinement is an ongoing activity that breaks items down until they are small and clear enough to be Done inside one Sprint — that, and not a number, is what makes an item ready for selection. Size is one of the details refinement adds, and the people who will do the work own it. The mechanism to carry: Scrum fixes who judges size and what size has to be small enough for, and deliberately leaves the unit, the tool and the timetable to the team.

Where this comes from

Cited
Scrum Guide section Product Backlog
What it says
Product Backlog items that can be Done by the Scrum Team within one Sprint are deemed ready for selection in a Sprint Planning event.

Practise this

Reading one question is not practice. The trainer will draw a set from objective 3 and space the ones you get wrong.

Practise Professional Scrum Master I

More questions on this objective

All questions on Managing products with agility