Evaluating Statistical Claims: Studies and Experiments

Observational study: Researchers observe and record data without intervening. Example: Comparing test scores of students who choose to attend tutoring vs. those who don't. Experiment: Researchers actively assign treatments to subjects. Example: Randomly assigning students to tutoring or no tutoring. Key difference: Only experiments with random assignment can establish cause and effect. Observat…

A confounding variable (lurking variable) is a variable that influences both the explanatory and response variables, creating a misleading association. Example: People who own boats tend to have higher incomes. It looks like boats → wealth, but the confounding variable is overall wealth (wealthy people buy both boats and other expensive things). Random assignment in experiments helps control fo…

Example: A study finds that coffee drinkers have higher rates of heart disease. Does coffee cause heart disease?