To achieve these goals, the programs needed an observation protocol that could be used by faculty member observers to reliably characterize how students and instructors were spending their time in undergraduate STEM classrooms. A critical requirement of the protocol was that observers who were typical STEM faculty members could achieve those results with only 1 or 2 hours of training, as it is unrealistic to expect they would have more time than that available. In the quest for a suitable observation protocol, multiple existing options were considered, and ultimately rejected.