ACT Preparation / Unit 21 ACT 2013 short lesson, about 20 seconds
Association and Cause in Science
Captions available
The idea
Two measurements that rise and fall together are associated, but that alone does not show one causes the other. Testing cause takes a controlled experiment, ideally with random assignment.
In practice
In invented data, sites with more moss also had more snails; both may follow the amount of shade.
Where people slip
Ask what third factor could drive both measurements.
Your place on the trail
Every lesson rests on earlier ones and opens later ones. Tap any to jump.
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