This case study examined interaction patterns between men and women and the effects of the patterns on gender participation in online debates. Students labeled messages to identify each message as an argument, challenge, evidence, or explanation when posting messages to the debates. The results revealed no differences in the number of male and female challenges elicited by male versus female messages, number of male and female rebuttals (e.g., explanations and counterchallenges) elicited by male versus female challenges, and the frequency of challenges and explanations posted by men versus women. These findings suggest that gender differences in communication styles do not necessarily produce gender differences in response patterns and participation. Other factors such as male-female ratio and task structures can affect gender interaction patterns and gender participation. Nevertheless, this study demonstrated how interaction patterns can provide causal explanations for observed differences and similarities in male and female performance in computer-mediated environments.