In this chapter you will learn:

1. How controlled comparisons rule out rival causes
2. Three possible scenarios for the relationship between an independent variable and a dependent variable, controlling for a rival cause
3. How to set up controlled comparisons using crosstabulation analysis and mean comparison analysis
4. How to construct line charts of the relationship between an independent variable and a dependent variable, while holding a control variable constant
5. How to identify spurious  relationships, additive relationships, or interaction relationships in empirical data