a + (b1) Professor–Student Rapport + (b2) Humor + (b3) Student Engagement = (Ŷ) Student Ratings of Instructors
Teaching of Psychology (2015) - Comment
doi: 10.1177/0098628315569924  issn: 0098-6283  issn: 1532-8023 

Aaron S. Richmond, Majken B. Berglund, Vadim B. Epelbaum, Eric M. Klein