The purpose of this study was to use the Stages of Concerns (SoC) framework established by Hall and Loucks as a way to usefully identify types of teachers. Teachers who participated in the study were attending a professional development program called Great Expectations (GE). A modified version of the SoC questionnaire was used, so an exploratory factor analysis (EFA) of the modified questionnaire was conducted and identified a five factor structure. Using these five factors, a latent profile analysis was conducted to identify teachers. Three types of teachers emerged: enthusiastic teachers, teachers who were uninterested in the GE program, and teachers who were interested in the program but still had trepidations. These three groups were then compared on their emotions prior to the beginning of the GE program and their experience with GE. The quantitative results from this study are compared to qualitative results from previous research on teachers' SoC.