Showing Cause and Effect
As students identify factors, they often talk about how each factor is related to the problem. They now show those relationships on their maps by connecting factors with arrows. The relationships are entered in sentences with the form: "As A increases, B decreases/increases." For example, "as number of cars increases, accidents increase."
Sometimes when students try to put a factor into a relationship, they find a need to change their labels. (For example, "weather" doesn't cause accidents, "bad weather" does.) Students should be encouraged to change their factors if they need to. In this example, "weather" was divided into two factors, "snow" and "rain."
When the teams enter their relationships, they describe how the relationship works and what evidence would prove whether the relationship is valid.
Student teams are always interacting with each other and with the teacher. They should agree on what evidence would support a causal relationship and ways to collect that evidence. The teacher gets to interact too. Some questions that might come up here would be:
- Does an increase in road construction always decrease the number of lanes?
- Why do you think that increasing the number of trucks increases traffic jams less than increasing the number of cars does?
- Is there a way to word the "time of day" factor that would allow you to put it into a relationship? Why did you think it was a factor?