This study investigates student engagement in asynchronous forums in distance learning by focusing on the interactions of 204 students across four classes. It aims to understand interaction evolution and influencing factors over the course of each class. Data analysis reveals an initial high involvement that declines markedly over time for each class. This suggests a need for better pedagogical strategies in online environments to retain student attention. The decline is attributed to limited interaction, fewer collaboration opportunities, and self-regulation challenges for the students. Recommendations include designing courses to be more interactive and collaborative, enhancing instructor presence, and developing students' self-regulation skills. The findings emphasize the complexity of maintaining engagement in online learning and highlight the need for continuous pedagogical innovation.