Let’s look at the Purpose and Processes, two axes of the toolkit for analyzing Communities of Practice.
Obviously, purpose is an important starting point. A community has to define what it wants to achieve. The purpose may change over time and can even vary for different groups in the community; but clarity and consensus are crucial.
Etienne Wenger (Communities of Practice. Learning, Meaning and Identity) talks about ‘joint enterprise‘, resulting from a ‘collective process of negotiation‘.
Once it has been agreed what the community wants to achieve, the members have to define how they will achieve this : which processes and practices need to be in place. How will the communication be organised, how will the knowledge be shared and how will the community members learn from each other.
It is important that the community members realise that the responsibility to be successful is a group responsibility, not the unique responsibility of the community coordinator. They have to realise they have to make it happen, no one else will.
It is a good practice to create a community charter, preferably in a community launch work shop. The discussions among the members will create the necessary clarity and alignment in the group. The charter is the tool by excellence to introduce new members and align them quickly with the "old timers".
I used to make the comparison with a service club. If the intention is to create job opportunities for young graduates, the processes will be around social networking, probably between industry and schools. If charity is the main purpose, the processes will probably focus on fundraising.
In the end, several purposes can be aimed at simultaneously, but only those with the appropriate processes in place will ever be reached.