Now that we’ve covered nested models and interaction models, it’s important to understand which kinds of scenarios will lead you to which kinds of models. Below are several scenarios. For each one, describe whether you think it is a nested-model situation or an interaction situation and explain why.

a. A school district implements a new curriculum and then measures for an increase in test scores, but there is some concern that the curriculum might be better designed for schools that were already performing well and that it won’t work well in schools that have performance problems.

b. If a sports team spends more money and brings in some big-name talent, is the improvement in the team’s performance due to this talent, or is it due to the increased attendance at games that all players on the team respond to by performing better?

c. People in cities tend to be in better shape than do people in the suburbs. Is this because of the shorter commutes that people in cities have?

d. Who experiences more health benefits from having an active social network, men or women?