Instead of de-fining groups by starting and stopping dates and by a subjectmatter that cannot change, define them by whether there isa learning culture. If a group has none, it is fine to disband it.
But any group that has managed to create a culture should beasked not to let it die: if people want to leave and go on tosomething else, ask them to leave gradually so that new peo-ple can come in gradually. There will be different sorts oflearning cultures. They can slowly change. The subjectmatter can slowly change. Membership (including teachers)can change. But the learning culture, which is probably thestrongest aid in learning, would be preserved. - P140