…the other is infectious or sick (both of which are contagious states), a die is rolled to determine if transmission occurs. The infectious and sick stages last exactly one turn, so these individuals advance to the next state each turn until they are recovered, whereupon they are immune for the duration of the experiment. The simulation ends when nobody is infectious or sick. Students keep track of the counts in each category and plot graphs.Spreadsheet: The spreadsheet is pre-programmed for the SIR model with optional isolation of the sick and pre-vaccination. Pre-designed experiments can be used to explore the behavior of the model and the effects of control measures. Other experiments can be added by instructors or students.