The concept of ba seemingly has some similarities to the concept of `communities of practice'.Based on the apprenticeship model, the concept of communities of practice argues that members of a community learn through participating in the community of practice and gradually memorising jobs.
However, there are important differences between the concepts of communities of practice and ba. While a community of
practice is a living place where the members learn knowledge that is embedded in the community, ba is a living place where new knowledge is created. While learning occurs in any community of practice, ba needs energy to become an active ba where knowledge is created. The boundary of a community of practice is rmly set by the task, culture and history of the community. Consistency and continuity are important for a community of practice, as it needs an identity. In contrast, the boundary of ba is ¯uid and can be changed quickly as it is set by the participants. Instead of being constrained by history, ba has a `here and now' quality. It is constantly moving; it is created, functions and disappears according to need. Ba constantly changes, as the contexts of participants or the membership of ba change. In a community of practice, changes mainly take place at the micro (individual) level, as new participants learn to be full participants. In ba, changes take place at both the micro and the macro level, as participants change both themselves
and ba itself. While the membership of a community of practice is fairly stable, and it takes time for a new participant
to learn about the community to become a full participant, the membership of ba is not ®xed; participants come and go.
Whereas members of a community of practice belong to the community, participants of ba relate to the ba.
There are four types of ba: that is, originating ba, dialoguing ba, systemising ba and exercising ba, which are de®ned by two dimensions of interactions (see Figure 6). One dimension is the type of interaction, that is, whether the interaction takes place individually or collectively. The other dimension is the media used in such interactions, that is, whether the interaction is through face-to-face contact or virtual media such as books, manuals, memos, e-mails or teleconferences. Each ba offers a context for a speci®c step in the knowledge-creating process, though the respective relationships between each single ba and conversion modes are by no means exclusive. Building, maintaining and utilising ba is important to facilitate organisational knowledge creation. Hence, one has to understand the different characteristics of ba and how they interact with each other. The following sections describe the characteristics of each ba.