This study is the first assessment of the long term effects of computer conferencing. The use of PLANET and FORUM are described, and major users and conference characteristics are presented through excerpts from conference transcripts. Part I of the report focuses on the ways in which organizations used computer conferencing. Conference size and duration for each major user are characterized as to organizational style derived from transcript excerpts. In Part II, patterns of growth of the user population, message sending, the use of commands, and the use of time are examined, and "message sending" in synchronous and asynchronous computer conferences are compared with those in audio conferences and face-to-face meetings. Questionnaire responses from the user population are summarized in Part III. Conclusions are presented and discussed in terms of eight issue areas: (1) the relationship between cost and usage patterns, (2) size of the user base, (3) conference logistics, (4) leadership patterns and skills, (5) user working patterns and skills, (6) organizational adaptation, (7) management support, and (8) computer conferencing as a form of group communication. Appendices include usage and cost data, a summary of questionnaire responses, and a listing of Institute for the Future publications relating to computer conferencing. (RAO)