Why are communities of practice so interesting?A community of practice is a group of people sharing a concern or a passion for something they do and learn how to do it better as they interact regularly. In an organizational context this usually is a craft or a profession. Communities of practice can evolve spontaneously because people come together and engage in gaining and sharing knowledge. Or they can be created with that goal.
An example within an organization is the community of practice which developed around the Xerox customer service representatives. They began exchanging tips and tricks how to repair machines over informal meetings. Realizing the potential, Xerox created the Eureka project a database set up in order to share this knowledge across the global network of representatives. Apparently, the database has saved the corporation $100 million. 
What are the characteristic features of a community of practice?
- a domain defined by the members' interest and competence;
- a community as a result of members' engagement in joint activities like discussing problems and practices, exchanging information and providing support;
- a common practice, i.e. a shared repertoire of experiences, stories, tools, ways of addressing problems etc. 
It is through the process of sharing information and experiences with the group and building relationships that the members accumulate social capital. Social capital is a multi-dimensional concept, with both public and private aspects and it provides value to both the individual and the group as a whole. Putnam's concept of social capital for instance has three components: moral obligations and norms, social values (especially trust) and social networks (especially voluntary associations).  Applying Putnam's central thesis to communities one might say that a self-sustained community with a stable core of contributors has accumulated social capital successfully.
How do communities of practice differ from other communities? Communities of practice should not be confused with communities of interest or teams. A community of interest provides a place where people who share a common interest can "go", exchange information, ask questions, and express their opinions about the topic. Membership is not dependent upon expertise - interest in the topic is sufficient. Membership in a project team, on the other hand, depends upon expertise. But typically, project teams have designated members who fulfill a certain role during the project and, hopefully, teams are dissolved once the task is completed. However, the classification isn't always simple: What about a company-sponsored product support forum where heavy users with all sorts of professional backgrounds help one another? Or what about one's own network of professionals on LinkedIn? Wenger gives this guideline (and following the link you can download an evaluation framework):
A personal network, for instance, is rarely a community as people in the network are not likely to have much in common except for being connected to the same person in various ways; and they may not even know about each other (even though they are potentially connected from a networked perspective). Conversely the community of donors to a cause may feel a strong allegiance and identity with the cause they share. They know about each other because they know that there is money flowing toward the cause beyond their own donations. And yet they do not necessarily form a network (except potentially), as there may not be any interactions or direct connections among them. 
Are communities of practice really that effective?
|Source: Hemmasi & Csanda |
How can community management start up and cultivate a communities of practice?Although the concept had a strong focus on face-to-face communities initially, many of the recommendations Wenger et al. [11, 12] give, apply to online communities of practice as well. In fact some of them apply to online communities in general.
1. Build on a preexisting core group (or develop one): In preexisting social and organizational structures like personal networks or after an event (be it a meeting or a summit) one may be able to develop a passionate core group. Well-respected individuals can help with their personal network and later on with the coordination of the community. A core group is important because it can take on community projects and helps identifying important topics for the community.
2. Mentoring the community manager: The core group is even more important if the community manager is not a practitioner. Only an insider can fully appreciate the issues and challenges at the heart of the domain and the latent potential in emerging ideas and techniques, so a community manager from outside needs the assistance of a mentor.
3. Access to the community: In order to maintain a certain level of discussion,access controls may be an appropriate instrument. In fact, in some communities of practice assuring that members are among themselves may be even vital.
4. Clarify the topic: The focus should lie on topics important to the business and community members. Key thought leaders may be a great help in creating real dialogue about cutting edge issues.
5. Build strong ties among members: When the individual relationships among community members are strong, the events are much richer. Participants who know each other well often come to community events with multiple agendas: completing a small group task, thanking someone for an idea, finding someone to help with a problem. In fact, good community events usually allow time for people to network informally. Well-orchestrated, lively public events foster one-on-one connections.
6. Welcome all levels of participation: Wenger discernes three levels of participation which are fairly self-explanatory: participation in the rather small (10 to 15 %) core group, in the equally rather small (10 to 15 %) active group and peripheral participation (usually the majority). The boundaries are fluid and one and the same member may shift from one level to another because of time restrictions or a shift in the focus of the community. Making it easy to contribute and to access the community’s knowledge and practices may invite free-riding but - on the other hand - they are essential for participation.
7. Allow evolution: The nature of a community of practice is dynamic, in that the interests, goals, and members are subject to change, its forums should be designed to support shifts in focus.
8. Broaden the community's horizon by bringing input from outside: The members and their knowledge are the communities most valuable resource. Nevertheless it is also beneficial to look outside. Thus, practitioners will find new possibilities and even stimulate change.
9. Make the social capital salient: Participation is voluntary and so there must be something in it for the members. Therefore make the value of being a member salient - especially at the beginning.
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