Simpson's Paradox

Lecturer - Dr Usha Sridhar

The name Simpson's paradox was introduced by Colin R. Blyth in 1972.

Wikipedia (2021): Simpson's paradox, which also goes by several other names, is a phenomenon in probability and statistics, in which a trend appears in several different groups of data but disappears or reverses when these groups are combined. 

            "Psychological interest in Simpson's paradox seeks to explain why people deem sign reversal to be impossible at first, offended by the idea that an action preferred both under one condition and under its negation should be rejected when the condition is unknown. The question is where people get this strong intuition from, and how it is encoded in the mind. Simpson's paradox demonstrates that this intuition cannot be derived from either classical logic or probability calculus alone, and thus led philosophers to speculate that it is supported by an innate causal logic that guides people in reasoning about actions and their consequences. Savage's sure-thing principle is an example of what such logic may entail."

Activity 6: Discussion about the inherent ‘flaw’ in comparing two averages-POD groups

Useful links

-The Yale University: 1 2 3