AP Physics: Period
Half the class did experiments to model the period of a pendulum, while the other half did experiments to model the period of a spring. We have three types of springs, and their spring constants are different enough that you can’t test all three with the same mass. Next year, I might have students start by using one spring to test how amplitude and mass affect period, then check their model with a second spring.
Earth Science: River Features
Today, the curriculum called for notes on typical river features, followed by students looking for those features in topographic maps to classify rivers as young or old. Before we did any notes, I had students sort the rivers based on their own categories. They based their categories on things like width or windiness that resulted to very similar sorts to young and old and lead nicely into the vocabulary. When students went back to their groups to sort the rivers by age, I noticed students got less accurate, largely because they interpreted small curves as meanders, making rivers seem older.