Simpson’s Paradox: Definition, Cause, and Example
Task
You are asked to demonstrate your understanding of Simpson’s paradox in a statistics/analytics interview setting.
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Define Simpson’s paradox in your own words.
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Explain how data imbalance or confounding can create the paradox (i.e., why aggregation can reverse trends seen within subgroups).
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Provide a concrete, numeric example where a relationship holds within each group but reverses when the groups are combined.
Hint: Contrast aggregated results with stratified (within-group) results and discuss the role of a confounder.