Online participation in collaborative online learning environments is instrumental in motivating students to learn and promoting their learning satisfaction, but there has been little research on the technical supports for motivating students' online participation. The purpose of this study was to develop a visualization tool to motivate learners to participate actively in collaborative online learning communities and examine its effects on online participation, perceived learning, perceived satisfaction, team project performance, and usability. Two types of visualization tool were developed: the A-type for representing group participation and interaction between groups, and the B-type for representing group participation and individual participation. Undergraduate students (N = 118) were assigned randomly to one of three groups (A and B: experimental group, C: control group). The results showed that two types of visualization tools have significant effects on the perceived satisfaction, perceived learning, and team project performance. Regarding online participation, the B-type of visualization tool was found to be effective. The usability of the A and B groups was similar and many learners in both groups reported that the visualization tool motivated them to participate in online learning. Theoretical, empirical and practical discussions are provided based on the results.