Resumen
New methods for high school and college Physics instruction engage students in understanding the physical world by constructing and using scientific models to describe, explain, predict and control physical phenomena. Modelling many particle systems involves the need to introduce statistical approaches and to look at reality in a probabilistic way. This paper reports a teaching approach in which the history of Physics is used as a Case Study in order to allow students to assimilate a given sequence of thought long enough to feel that it has a context and a surrounding logic of inquiry and experience. This approach focuses on Boltzmann?s conjectures and reasoning aimed at introducing his stochastic models in a mechanist era. The kind of conjectures chosen are described and the structure of our teaching approach is outlined. It will also involve the pedagogical tools prepared in order to make workable the approach even for students not familiar with combinatorial and permutational calculus. Preliminary results of the first pilot test in two Courses for teacher training are also described