Scrum is built on the foundation that everyone required to go from requirements to potentially shippable product is on the same team, preferably in the same general seating area, if not, preferably in the same time zone. It is also recommended that someone is not on more than one team at a time.
This means that the business team member(s), the tester(s), and the developer(s) required to do the feature are on the team. This also means that if you ask the question “Were all the people required for this feature on the team” and the answer is no, then you are missing a big component of scrum. This has major implications and poses some significant challenges to organizations, particularly when they are trying scrum and haven’t organized their people or their workflow according to this concept.
Our guess is that one of the reasons for this recommendation is so that the team can work throughout the day in a fluid manner. Experience tells us that when you stick a bunch of people in a formal meeting, that it immediately becomes a wasteful activity. Not to say that you can’t get value out of meetings, but we think you can get much more value out of fluid communication throughout the entire day.