In this discussion you'll look at a few situations and think about whether causation may or may not exist. Some of the scenarios below indicate the possibility of cause and effect, and some don't. A study of 50 cities in North America finds a strong correlation (r = .75) between the number of teachers employed in a city and the dog food sales in the city. Are the teachers encouraging people to buy dog food? Are there any other factors or causes to consider?

A study of 30 developing nations finds a strong correlation (r = .82) between the number of radio stations per capita and the number of new cancer cases reported each year. Do radio stations cause cancer? Are there any other factors or causes to consider?