The nine students in the Modeling Your World workshop this afternoon were learning to model certain kinds of functions with Rob in Vensim. Using the example of Romeo and Juliet, whose change in love for each other is determined based on differing rules, Rob showed how changing the rules that define the change in their love changes the system. He changed the rules of the model to have Romeo and Juliet fear the other's attraction, creating a circular graph that Rob explained modeled a predator-prey relationship with its cyclic nature: as one goes up, the other decreases; as it decreases, the other rises, endlessly cycling.
After this introductory activity, Alexandra and Rachel gave a demonstration introducing the class to NetLogo, turtles (the agents of NetLogo), and functions. Before the class went on break, they played a game in which they were to write instructions for a robot to make a peanut butter sandwich in order to get used to the logical methods of NetLogo. The students leaned that they could not assume that their computers know anything and they are required to spell out each instruction. After the students' break, Alexandra showed a model on the Shodor website of disease that was made in NetLogo. The students studied the effects of changing the parameters of a model, noticing how many people survived the infection given different starting conditions. After manipulating the settings for a while, the students downloaded a simpler infection model in order to look at the code of the model. Alexandra went through the code with the students, helping them to understand what each line meant. Afterwards, the students began to learn to make changes to the model, for example, adding an ambulance that healed sick agents. The students ended the day having gained basic idea of NetLogo and a better understanding of modeling.