The purpose of this study was to develop a valid, reliable, and brief measure of active learning in college classrooms that is cheap and easy to complete and yields results that faculty can easily use to inform their development as instructors. Initial construct and face validity was achieved by modifying existing instruments and creating a draft of a brief measure of active learning for external expert review. Following the suggested revisions, the engaging classroom observation was then piloted and revised as necessary. Reliability was tested and measures of internal consistency and interrater reliability were acceptable. A principal component analysis showed two components that were moderately correlated, which indicated the potential they could be combined. An Exploratory Factor Analysis confirmed the instrument is measuring one factor, which we propose as active learning. This study is significant because it offers a brief instrument based on students' perceptions that can be used formatively by faculty.