The SIRs actually measure a number of variables and identifying those that might be most closely associated with the underlying pedagogy of a course are difficult to identify. Instead, I chose to look at just one of the SIR-generated ratings, the Overall Evaluation of the course. This is clearly designed to be an overall indicator of effectiveness. A large change here (in either the positive or the negative direction) would seem to be a clear indication of success or failure from the student's perspective.
Furthermore, my assumption at the beginning of the course was that there would be a large change in one direction or the other. I assumed that students would either love this approach or hate it and that this would be reflected in the SIR results. The chart below, which contains the weighted average of the Overall Evaluation score (1-5 with 5 being best) for all classes taught in a particular year, indicates that I was wrong: