July 1, 2005

The class started with a brainteaser while waiting for a few latecomers. It involved 3 containers that held 3, 5, and 8 liters of water in them. The object of the puzzle was to measure out 4 liters into one of the 3 containers.

Once everyone had arrived, David reviewed the different applications used and how different programs could be used to study the same thing. For example, David went over flow charts in Vensim and Stella. He linked the beginning puzzle to the fact that people think logically. David illustrated this using flowcharts.

After snack he introduced the students to NetLogo and pulled up the Head for the Hills model. The object of this activity was to get the people to the highest hill. This model made the students think about the different factors that need to be considered, like the smoothness of the plains. He then discussed the major components of NetLogo. These parts are turtles, patches, and the observer. This led into the topic of how programs use similar parts. David then walked the students through programming a model of their own.

The students talked through problems programmers need to think about like errors, logical values, working code, and informative comments. They talked about how tags that are left out or misspelled can lead to errors. Also, they talked about conditions that need to be true for the turtle to move to a higher peak, and then they thought through how they could code these conditions.