The question of how to best design an online course that promotes student-centred learning is an area of ongoing research. This mixed-methods study focused on a section of advanced high school students, in college-level mathematics courses, that used a synchronous online environment mediated over web-conferencing software, and whether the affordance of multiple communication channels and student-centred activities affected involvement, cohesion, and satisfaction. Study participants reported that anonymous input and group work activities encouraged their involvement in learning activities, increased their satisfaction, and fostered social cohesion. Although the on-going management of technical issues limited student involvement and satisfaction, there were no differences in final grades obtained by students participating in this delivery format and their peers participating in an alternate learning environment facilitated by video-teleconferencing. This study offers supporting evidence that a student-centred learning environment mediated over web conferencing software can foster social cohesion, student involvement, and student satisfaction.