Question 1
Observation: Water quality improved after the factory installed filters
What causal inference is most reasonable?
This inference uses temporal precedence (the cause occurred before the effect) and correlation to suggest causation: The filters likely improved water quality
However, be aware of alternative explanations (confounding variables, regression to the mean, etc.) that might also explain the observation.
However, be aware of alternative explanations (confounding variables, regression to the mean, etc.) that might also explain the observation.