The Internet has created an environment where many technologies are used to provide net-based customer services. Recently, Online Live Chat Customer Service (OLCCS) has been adopted widely and rapidly on many websites. OLCCS extends traditional customer service channels by using live chats to deliver real-time help and on-demand assistance to online customers’ inquiries. The purpose of this dissertation is to investigate the moderating effects of dyadic communication style and task on the relationship of media synchronicity and performance. Based on Media Synchronicity Theory, lower media synchronicity (text only) will be more appropriate for response tasks; while higher media synchronicity (text and co-browsing) is more likely to improve the performance of procedural tasks. The nature of the dyadic communication style, either implicit or explicit, will also affect the connection between media synchronicity and performance. In addition, the analysis of this dissertation focuses on the level of dyad (representative and customer) that uses text and co-browsing in live chats. The research site selected for this dissertation is a large university library located in the northeastern United States. Excerpts of transcripts were collected from 362 chat sessions in 2004. Content analysis will be used to code these excerpts. Values for the constructs will be assigned based on the coding. ANOVA and multiple regressions will be performed to test the proposed hypotheses.