College Algebra is a prerequisite for calculus and is thus an important stepping stone in the careers of STEM-intending undergraduates. However, College Algebra has low pass rates across the United States, interrupting students’ pathways to success. To address this concern, a research-oriented university in the Northwest United States restructured its College Algebra course to increase student engagement and active learning practices. Despite a new common curriculum, wide variation in the mathematical content that is presented by instructors was observed. Through the lenses of three observation protocols applied to video recordings of College Algebra classrooms, this thesis investigates the mathematical content present in lessons covering two mathematical concepts, evaluates the protocols for their ability to capture the variation in mathematics, and synthesizes these results to offer ideas for future research in College Algebra instruction. Claire's major professor is Prof. Mary Beisiegel.