1. Correlation Example: School closed for a week and nobody else got Swine Flu. Correlation: closing school stopped it spreading! But did the closure really cause it to stop spreading? How can we be sure it wasn’t a coincidence? Correlation = a link or relationship between two things that happen.

2. The more firemen fighting a fire, the bigger the fire is going to be. Therefore, firemen cause fire. Is this a sensible correlation? Answer: No! It’s the other way around. Fire “causes” firemen.

3. Sleeping with your shoes on is strongly correlated with waking up with a headache. Therefore, sleeping with your shoes on causes headache. Is this a sensible correlation? Answer: Not normally! It’s more likely that they are coincidences because of a third variable (being drunk).

4. As ice cream sales increase, death by drowning increases sharply. Therefore, ice cream causes drowning. Is this a sensible correlation? Answer: No! They are both things that happen more in summer.

5. People are taller today than 500 years ago. Health and diet have improved over the last 500 years. Therefore, better health and diet have led to people becoming taller. Is this a sensible correlation? Answer: It makes sense. It’s also why people live longer. We still need proof though!

6. As the number of pirates has decreased, global warming has increased. Therefore, global warming is caused by a lack of pirates. Is this a sensible correlation? Answer: No! We don’t need more pirates! These are completely unrelated and are a coincidence.

7. During summer, people get hayfever. There is also lots of pollen in the air. Therefore, pollen causes hayfever. Is this a sensible correlation? Answer: Yes, it makes sense and there have been studies to prove it.

8. Two unrelated things can show a correlation. Just because we have a correlation doesn’t mean it’s true! It doesn’t mean one thing causes the other. For that, we need scientific evidence! Sometimes it’s pretty difficult to get. So… what does this all mean?