Simpson's Paradox
Definition
Simpson's Paradox happens when a trend seen in different groups reverses or disappears when those groups are combined. It's a statistical effect that can mislead analysis if not checked. This usually occurs because hidden or confounding variables are influencing the outcome.
Why It Matters for Marketers and Analysts
For marketers or analysts, Simpson's Paradox highlights why data segmentation matters. Without breaking results into relevant groups, brands may make wrong conclusions and base important business decisions on inaccurate findings. Simpson's Paradox reminds businesses that context matters, and raw averages are not always reliable indicators of real performance.
Where It Commonly Occurs
This paradox is common in A/B testing, healthcare data, and social science research.
Example
Two marketing campaigns might look effective in small customer segments but show opposite results when combined. That's because hidden factors, like customer demographics, may distort the trend. The best way to avoid mistakes is to carefully analyze subgroup data before making decisions.