The product owner and the developers get work ready for sprints in an activity called Product Backlog Refinement. Product backlog refinement, sometimes called backlog grooming in reference to keeping the backlog clean and orderly, is a meeting that is held near the end of one sprint to ensure the product backlog is ready the next sprint. During a product backlog refinement meeting, the team and product owner discuss the top items on the product back log. The team is given a chance to ask many of the questions that would normally arise during sprint planning. Perhaps questions like, what should we do if the user enters invalid data here? Are all users allowed to access this part of this system? What happens if? If those questions were asked for the first time during sprint planning and too many could not be answered, it might be necessary to put a high-priority product backlog item aside and not work on it during the sprint. By asking these questions before the Sprint Planning Meeting, the product owner is given time to figure out answers he or she may not prepared to answer immediately. In fact, sometimes the backlog refinement meeting ends with more questions than answers, and that's OK. Remember that the whole point of doing backlog confinement is to alert the product owner to high-priority items that are not well understood so that they can be made clearer in time for the sprint planning meeting. Backlog refignment, in that sense, is really a checkpoint rather than an effort to fully resolve issues. I like to hold the product backlog refinement meetings two or three days before the end of the current sprint. This gives the Product Owner sufficient time to act on any issues that are identified. Some teams find that doing shorter meetings every week rather than once per sprint is more suited to their cadence. And that is, of course, fine. Many teams will have the entire team participate. There are two big advantages to doing so. First, everyone hears the product owner's answers. Second, it allows the teams to estimate product backlog items as they are discussed. The drawback to having everyone participate is that more person hours are spent on refinement. My personal view is, that having half or slightly more than half of the team participate, along with the product owner, and ideally the scrum master, is sufficient. With half the of team present, not as many questions will be asked. And that's a shame. But I suspect that with half, or so, of a team president, they still think of 80 or 90% of their questions. The big advantage to this is that in almost every sprint, there will be a person or two who is frantically busy with only two or three days left in the sprint. If that person has to attend a refinement meeting, it may mean they need to work late one evening or that a bit less functionality is delivered in this sprint Experiment with both approaches and see what works best for your team. Some teams need to be cautioned about spending excessive time refining their product backlogs. A general rule of thumb is that no more than 10% of a team's total time available within a sprint should be spent on backlog refinement. That includes the meeting itself, as well as analysis and other work that may be spawned from a refignment meeting.