Page 77 - Getting the Picture Modeling and Simulation in Secondary Computer Science Education

Defining and Observing Modeling and Simulation in Computer Science
That remains to be done” and went on to change the code. Later on they tried again. S6b: “And if we make this one a bit lower, say seven or so, then they die, that is really abrupt, like, either they live or so, or all dead.”
In the project documentation, all of the students reported that their models
behaved as expected (validation). Several students described validating their
models and adjusting when necessary. To this end, Team 1 wrote: “to prevent
particles from reacting with each other immediately following a reaction, we built in
a reaction pause. [...] That way you prevent particles from being stuck in a constant back-and-forth reaction.” 3
Experiment. Team 7 was the only team who documented systematically performed experiments with their model: they reported the initial parameter values (e.g. ten cats and nine mice) and included the resulting data plots in their project documentation. In the recordings we saw other students engage in experimenting to various degrees, but most failed to mention this in the project documentation.
Analysis. Not all the students provided an analysis of the results of the experiments, but in the project documentation, they all reported answers to the purpose of their models. Team 7’s analysis revealed, “The mousetraps were not always effective. Some mousetraps go off but the mouse manages to escape.” Finally, they concluded that mousetraps were more effective than cats in catching mice. In the recordings we saw Team 3 analyze their data, without reporting it in the project documentation, and their conclusion was, “We expected that the new medicine would decrease the spreading of Ebola. It turned out that the medicine worked rather quickly, but that the rate of infectiousness was of influence as well.”
Reflection. As required, all the students reflected on their models in the project documentation. Team 7 wrote: “Not everything in our model corresponds with the reality. But it is nice to experiment with it. You can make your model as large and complex as you wish.” In the survey the students were asked what they learned. S3b wrote: “It [modeling] is a good means to predict/research hypotheses. A good aid for research. I take chemical reactions as an example. You can make it and thus see (visualize) what happens,” a thought reflected by S1a too. S4a learned that it was important to have a clear idea of the purpose of the model before engaging in the modeling process and that models and simulations never completely correspond to the reality. Contrary to S4a’s reply, during the interview S1a expressed his astonishment about how easy it was to make a model that “actually reasonably corresponded” to what was modeled. He even went on to show it to his chemistry teacher.
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