Distinguish correlation from causation and reason about limitations of observational studies.
18 original evaluating statistical claims questions in the SAT Ranker bank, with instant scoring and an Elo-based rank once you sign up. Below are a few free samples with full explanations.
A study finds a strong positive correlation between number of firefighters at a fire and size of the fire. Which choice best describes a limitation of concluding that number of firefighters at a fire directly causes size of the fire?
Correlation does not by itself establish causation; a confounding variable could explain the relationship (here, that larger fires both require and are fought by more firefighters), which is why the study alone can't prove direct causation.
A study finds a strong positive correlation between hours spent studying and exam scores. Which choice best describes a limitation of concluding that hours spent studying directly causes exam scores?
Correlation does not by itself establish causation; a confounding variable could explain the relationship (here, that study habits also correlate with other factors like sleep), which is why the study alone can't prove direct causation.
A study finds a strong positive correlation between household plant ownership and self-reported happiness. Which choice best describes a limitation of concluding that household plant ownership directly causes self-reported happiness?
Correlation does not by itself establish causation; a confounding variable could explain the relationship (here, that people with more free time or income may have both), which is why the study alone can't prove direct causation.
A study finds a strong positive correlation between coffee consumption and reported alertness. Which choice best describes a limitation of concluding that coffee consumption directly causes reported alertness?
Correlation does not by itself establish causation; a confounding variable could explain the relationship (here, that people who are already busier tend to drink more coffee), which is why the study alone can't prove direct causation.
A study finds a strong positive correlation between time spent on social media and reported anxiety levels. Which choice best describes a limitation of concluding that time spent on social media directly causes reported anxiety levels?
Correlation does not by itself establish causation; a confounding variable could explain the relationship (here, that people already prone to anxiety may use social media differently), which is why the study alone can't prove direct causation.