The number of online courses in higher education is on the rise. However, empirical evidence elucidating best practices for synchronous online instruction is needed to best implement these courses. The research purposes were to examine synchronous online class sessions to (1) quantify interaction type, frequency, and rate, (2) quantify student engagement frequency, and (3) quantify instructor prompt frequency in three areas in order to investigate relationships with each category of student engagement. A total of 24 previously recorded synchronous sessions including oral and textual chat interactions were transcribed. Every line of student interaction was determined to be either superficial or containing evidence of at least one instance of engagement according to five categories from the Seven Principles and the National Survey for Student Engagement. Every line of instructor interaction was concurrently coded for at least one of the following forms of prompt: social, organizational, or intellectual. Inter-tester reliability of coded interactions from Cohen's kappa = 0.91. Social prompts were the best predictor of supportive campus environments (r = 0.79); organizational prompts were the best predictor of enriching academic experiences (r = 0.72); and intellectual prompts were the best predictor of instructor interactions, active/collaborative learning, and academic challenge (r= 0.77, r= 0.78, r= 0.54, respectively); with all of these being significant (p< 0.01). The conclusions are: (a) online synchronous class sessions can be used to promote student engagement across all NSSE categories, (b) online synchronous class sessions can be moderated via differing instructor-prompts to promote student interaction and engagement.