In this paper, we describe our experience with the longterm, widespread use of CoWeb, an asynchronous collaborative tool that is mostly used to complement existing faceto-face groups (such as classes). The CoWeb is an openended tool that does not enforce or explicitly support specific roles or usage, yet several well-defined uses and roles have emerged over time. In our design methodology, we recognize these roles and refine our collaboration environment to better support them. Keywords CoWeb, Wiki, CSCL, roles, website, long-term, design methodology