Chatty reference · stats1 week 4
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2026-08-16T00:00:00.000Z
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ChatGPT archive slice for week 4. # 24.
24. Stats W4 — Association Between Two Variables
Officially includes categorical association, contingency tables, numerical association, scatterplots, covariance, Pearson correlation and point-biserial correlation. citeturn1view1
Categorical × categorical
Contingency tables.
Numerical × numerical
Scatterplot.
Covariance
Conceptually:
Do two variables tend to move together?
Pearson correlation
Interpret:
- sign → direction
- magnitude → strength of linear association
Point-biserial correlation
Useful when:
- one variable is binary/categorical
- one is numerical
Major trap
Correlation ≠ causation.
And:
does not mean "no relationship whatsoever"; it primarily indicates little/no linear association.