This paper describes a computer simulation for educating teachers in classroom planning and decision-making. The simulation was based on research by Borko and Cone. The former explored teachers' preinstructional decisions and classroom objectives; the latter focused on decisions about managing student behavior. In both studies, scenarios were used to describe student characteristics and behavior, and the teachers made pedagogical decisions about the students. The scenarios were based on factorial designs which systematically manipulated variables known to be important in teacher's decisions. The simulation uses a fractional factorial of the full experimental design to reduce the number of scenarios the teacher needs to respond to in the simulation while permitting the simulation to estimate the teacher's decision-making policy (details of fractional factorial designs are presented in the paper). The program then compares the teacher's observed policy with the ideal decision model also obtained from the teacher. The teacher has the option to modify the ideal, the observed, or both policies and to re-run the simulation with a new set of scenarios. A concrete example is provided to illustrate the simulation and results.