Correlation and causation

Slides for “Correlation and causation”

Control questions:

1. Is heavier rain correlated with more umbrellas in the street?
2. What is the causal relationship between heavier rain and proportion of umbrellas in the street?
3. Why do we use controlled experiments?
4. Why is randomization important in this context?
5. What is the difference between an observational study and an experimental one?
6. What is a confounder?