The population characteristics that influence population growth and the spread of a disease in the population are summarized in graphical form in the flow chart display. The flow chart gives a graphical depiction of the way that the models underlying Epidemiology work. The host population is broken down into several categories. The simulation model keeps track of the number of individuals in each category and describes the rate individuals enter and leave each category. This would represent individuals who had the disease, but are now losing their immunity and hence becoming susceptible to infection again.
Individuals can leave the susceptible category in two ways, through death or through infection.
The Flow Chart display for a simple epidemiological model. Each value can be changed by the user by either moving the slider or by typing in a number in the number box to the right of the parameter's name. The Settings Panel allows the user to manipulate a variety of parameters that will influence the rate of spread of a disease in a population. Click on the name of a parameter for a more detailed explanation. For example, if you wanted to model bubonic plague in Medieval and Renaissance Europe, you might want to set initial time to 1300.