This study examined the role of course engagement in college student success, especially for students who have multiple life commitments and few social supports.Building on previous measurement work and based in self-determination theory, the study was organized in five steps. Relying on information provided by 860 undergraduates from 12 upper and lower division Psychology classes, the first step was to improve the measurement of course engagement, by mapping the increased complexity found in self-reports of college students (by incorporating items capturing engagement in "out-of-classroom" activities and general orientation, to standard items tapping classroom engaged and disaffected behavior and emotion). 12 items were selected to create a brief assessment covering the conceptual scope of this multidimensional construct; its performance was compared to the full scale and found to be nearly identical.Second, the assessment was validated by examining the functioning of course engagement within the classroom model: As predicted, engagement was linked to proposed contextual and personal antecedents as well as course performance, and fully or partially mediated the effects of both context and self-perceptions on actual class grades; findings also indicated the importance of including a marker of perceived course difficulty. Third, the university level model was examined, which postulated key predictors of students' overall academic performance and persistence toward graduation.Unexpectedly, academic identity was found to be the primary driver of persistence and the sole predictor of GPA; moreover, it mediated the effects of learning experiences and course engagement on both outcomes. College success and student engagement / iiThe fourth and most important step was to integrate the classroom and university models through course engagement, to examine whether students' daily engagement predicted their overall performance and persistence at the university level. As expected, course engagement indeed showed a significant indirect effect (through academic identity) on both success outcomes, and these effects were maintained, even when controlling for the effects of university supports. Finally, student circumstances were added to the integrated model, specifically focusing on whether course engagement buffered cumulative non-academic demands on performance and persistence. Although unexpected, most interesting was the marginal interaction revealing that students whose lives were higher in non-academic demands showed the highest levels of persistence when their course engagement was high (and were the least likely to return next term when their engagement was low). Future measurement work and longitudinal studies are suggested to examine how course engagement cumulatively shapes academic identity, especially for students with differentiated profiles of non-academic demands and supports. Implications of findings are discussed for improving student engagement and success, and for using the brief assessment of cours...