In recent years, synchronous online peer response groups have been increasingly used in English as a foreign language (EFL) writing. This article describes a study of synchronous online interaction among three small peer groups in a Taiwanese undergraduate EFL writing class. An environmental analysis of students' online discourse in two writing tasks showed that meaning negotiation, error correction, and technical actions seldom occurred and that social talk, task management, and content discussion predominated the chat. Further analysis indicates that relationships among different types of online interaction and their connections with subsequent writing and revision are complex and depend on group makeup and dynamics. Findings suggest that such complex activity may not guarantee revision. Writing instructors may need to proactively model, scaffold and support revision-related online discourse if it is to be of benefit. (Contains 3 tables.)