The fact that event A is correlated with event B does not imply that A causes B, because:
- the correlation might be accidental
- the causal direction is the reverse one
- there is a hidden common cause
- the correlation is due to side effects
Other topics: good evidence for causation, and special terms for describing causal connections
A nice video about the placebo effect
1. Evaluate these arguments and in particular think about possible alternative explanations.
(a) J&J's new bandages are very good at promoting wound recovery, 89% of those surveyed agreed that they wounds have improved significantly after using the bandage for 5 days.