This is the process of creating stories, decomposing stories into smaller ones when they are too large, refining the acceptance criteria for individual stories, prioritizing stories on the product backlog and sizing the existing stories in the product backlog using effort/points. During each sprint the team should spend time doing product backlog refinement to keep a pool of stories ready for the next sprint. Meetings should not be longer than an hour. Meeting does not include breaking stories into tasks. The team can decide how many meetings are needed per week. Though everything can be done in a single meeting, these are commonly broken into two types of meetings for efficiency: The refinement meeting, where the product owner and stakeholders create and refine stories on the product backlog. The planning poker meeting, where the team sizes the stories on the product backlog to make them ready for the next sprint.