There are several different types of online communities. Chat rooms, forums, newsgroups, and email lists all have their particular form and function. In many cases, a community may consist of one or more of these types. Static web pages and guest books may also contribute to the form and content of the community. Members of a particular group may participate in one or all of the parts that make up the community.
Examining any online community, a forum for example, one will likely see the following hierarchical structure: a webmaster, the administrator, moderators and visitors. There may be some overlap within these roles. Visitors can also be broken down into types, which may or may not be according to a hierarchy: regular visitors, casual visitors, newbies and lurkers. (Rheingold, 1993, Wallace, 1999)
According to Hagel and Armstrong, community structure and evolution can be broken down into four types: virtual villages, concentrated constellations, cosmic coalitions and integrated infomediaries. Virtual villages, the lowest form, are highly fragmented entities. Integrated infomediaries are tightly coupled groups of communities that are very specialized in one or two particular areas, but branch out to fulfill customer needs in a variety of related areas. (Hagel and Armstrong, 1997) Concentrated constellations are niche communities dedicated to a particular topic with several core communities communicating with each other to achieve maximum effectiveness. The sub-communities share a fair amount of information and will work together to achieve whatever goal the group deems necessary (Aaker, Lee, 2001, Bagozzi, 2002, Wallace, 1999).
Online communities are socially oriented groups of people. Their primary function is communication. Members may or may not have common interests, depending on the goal of the community. Online communities have shared responsibilities and a set of mutual obligations. These are defined either by a written code such as a Terms of Service, or by an unwritten code of mutually understood and agreed upon practices. The larger the community, the more likely the code is to be written down.
Aaker, J. L., Lee, A. Y., "I seek Pleasures and We Avoid Pains: The Role of Self-Regulatory Goals in Information Processing and Persuasion," copyright 2001, Journal of Consumer Research Inc, Vol 28, June 2001
Bagozzi, R.P, Dholakia, U. M., "Intentional Social Interaction in Virtual Communities," copyright 2002, Journal of Interactive Marketing, Vol 16, Num. 2
Hagel, J., Armstrong, A., "Net Gain: Expanding Markets Through Virtual Communities," copyright 1997, McKinsey & Company Inc., Harvard Business School Press
Rheingold, H., "The Virtual Community: Homesteading on the Electronic Frontier," copyright 1993, Harper Collins
Wallace, P. "The Psychology of The Internet," copyright 1999, Cambridge University Press