This report validates a novel quantitative methodology for analyzing moment-to-moment interactions in classrooms called the Poisson Process Methodology (PPM). PPM differs from moment-to-moment qualitative and quantitative analyzes typically used in education by using time-series data to quantify the degree to which the presence of facilitator moves affect the future rate of student actions. Using PPM in the context of small-group problem solving further validates the use of the method in several settings in education. We applied the method to data from a larger study about students' engagement in reasoning abstractly and quantitatively as they worked on mathematics problems with a facilitator. We present empirical results of PPM performed on two semi-structured interviews involving a facilitator and two students, which led to some interpretable results that extend previous understandings of forms of talk that promote quantitative reasoning.