He developed ePREP based on the internationally recognized Prevention and Relationship Education Program (PREP; founded by Howard Markman and developed over decades with Markman, Scott Stanley, and their team at PREP, Inc.). Braithwaite saw the need for making relationship education more widely available to people through electronic dissemination. He, along with his colleague Frank Fincham, began to test ePREP in 2004, having now published four studies on it. Beyond on ePREP, his primary research interests center on preventing marital distress and divorce as well as enhancing marital health. He also studies basic processes such as why some marriages thrive while others fail and how partner selection influence marital health and stability. Finally, he is interested in the association between close relationships and physical or mental health.