The overwhelming consensus amongst educators is that different learners achieve success through a variety of teaching and learning styles. While frontal, Socratic-style teaching is the most dominant mode known to the West for the past four thousand years, modern technology has created a space for the development of novel, student-centered methodologies of learning and teaching. However, in STEM1 courses frontal-style lectures are common at universities. Over the past decade, in an effort to help more students succeed in STEM courses, active learning modes such as the studio classroom or the flipped classroom, have been piloted, developed, and validated at several universities for large, mandatory courses. The flipped classroom aims to engage students in active learning by restructuring the time and tasks performed in- and out-of-class. Content is relayed to students outside of class hours through such methods as online tutorials, clips of video lectures, textbooks and pre-class exercises. Exercises such as problem solving, which would traditionally be assigned as homework, are then brought into the classroom. Classroom time is mostly devoted to solving problems through group collaboration and peer-facilitated learning. Previous studies conducted at MIT for the instruction of physics have demonstrated tremendous student gains in the cognitive and affective domains using quantitative methods such as conceptual questions, quizzes, and examinations as well written feedback as a qualitative measure. The researchers in the larger study aim to better understand for whom the flipped-classroom environment is a good fit in terms of maximizing student achievement through positive affective engagement. In this more focused study, the researchers aim to find a relationship between the spectrum of a student’s affective responses and his/her academic performance across eight categories, detailed below. Over the course of two semesters in the 2013-2014 academic year, a flipped-classroom course design was developed for a Mathematics for Computer Science course required for all incoming Computer Science majors at the Massachusetts Institute of Technology (MIT). Two conditions were offered to students; while all students would undergo the flipped-classroom setting, students who so desired could also participate in a Project Based Learning activity that would be submitted before the final examination. The comprehensive study included approximately 300 undergraduate students. To assess affectivedomain engagement, students were given the opportunity to provide written feedback regarding the course in general, and the flipped classroom and the project-based learning in particular. The written statements were analyzed for terms and phrases regarding affective engagement across eight categories: assessment, attitude, course format, self-efficacy and learning style, teaching, teamwork, and workload. Each statement will be read and assigned to at least one of the aforementioned categories, which were developed according to the literature and a grounded-theory approach. The preliminary statement analysis will be validated by other researchers also guided by the experts. Finally, the anonymized student feedback will be paired with the individual student’s assessment performance metrics and statistics. This study aims to contribute to the body of knowledge relating to the active learning modes and their effect on undergraduate affective-engagement in large, mandatory, STEM courses at institutions of higher education. 1 STEM – Science, Technology, Engineering, and Mathematics