During the Fall term of 2012, 16 SESs, who are highly trained and experienced classroom observers, used this evolving protocol to observe a variety of courses in singles, pairs, or trios across most of the departments in the UBC Faculty of Science (including the disciplines of biology, computer science, earth sciences, mathematics, physics, and statistics). We analyzed the SES generated observation data to identify coding disagreements and met with the SESs to discuss the evolving protocol and coding. These discussions covered observed behaviors they found difficult to code and/or hard to interpret, and other important elements of instructor or student behavior they felt were not being adequately captured. The protocol evolved through five different versions during this stage of testing and feedback. The final version had substantially simplified categories and all identified problems with the wording on the codes had been eliminated. Notably, it was quite simple to reliably code classes taught with traditional lectures, as a very small number of behaviors need to be coded. Therefore, the majority of the work went into improving the protocol so it could reliably characterize classes that had substantial and varied interactions between instructor and students and multiple student activities.