Online communities (OC’s) depend on shared interests and user interactions mediated by technology. Successful OC’s find ways to encourage these interactions to grow communities. Many OC’s have influential users that help grow the community by their very presence and contributions. However, the process for identifying users having the greatest impact is not trivial. This study offers a new method for identifying these influential users through the creation of modified Hirsch indices, which improves upon the current method of using contribution counts or a survey method of polling other users. We validate the new measures against user status and then analyze the measures by correlating them against postings, thread starts, and views and replies to the thread starts for a shared interest OC.