As part of my study of an online community I have to measure the participation rates among participants, in a way similar to Nancy Baym's in her classic study of the r.a.t.s online community. From my participation and observation of this particular community so far, it is obvious to me that most of the messages are contributed by a small group of heavy users. However, I need to quantify it, measure it and present it as a table containing percentages of posters and posts contributed. My question is how can I do it? What is the method of measuring these rates? Does it simply consist in noting down how many messages each member writes? Prima facie that may look like an easy procedure but once starting to do it it turns out to be extremely difficult since this online community is made up of more than 20 conferences each one comprising more than 50 different topical discussions. Overall the number of messages written every week is enormous. Any ideas on how I can measure overall participatio rates of such an environment? Thank you, K. Diamantaki