Copper website you can find a link to a webcast with Bill Snyder (also called in the same introduction William M. Snyder (?). He talks about what a community of practice is, and how it worked in the case of the Copper group (a CoP in higher education).
A community of practice is a group of practitioners connecting over time to learn and collaborate together. The social component is important as it generates trust and comfort to be able to ask each other questions. He explains the elements of a community of practice: domain, practice and community.
For the Copper group, the domain had been identified during a congress where various campuses could nominate the kind of issues they were interested in, and could rate their interest and expertise to share. Topics were for instance, inclusiveness, service learning and assessment. Various in-campus and inter-campus activities took place like teleconferences, f2f meetings, campus visits and newsletters were produced. The campus visits have an important place because they give a chance to see practice in context.
At the end the interviewer asks how why a community of practice is important, as it takes up time. He answers there are two elements (I heard four):
1. the research component, researching new teaching and learning
2. the practice- translating research into practice, for instance for a new approach to maths, how to apply it in the classroom
3. professional development
4. reputation building