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Visualizing a correlation with a third variable

Source: interviewintermediate

WHAT IT TESTS: Bivariate viz plus confound awareness. OUTLINE: A scatter plot with a trend line shows the relationship; encode network type by color or facets to expose a lurking variable. RED FLAG: Treating the correlation as causal.

WHAT IT TESTS: Whether you pick the right chart for two continuous variables and reason about confounding. ANSWER OUTLINE: Plot load time on the x-axis against session duration on the y-axis as a scatter, with a regression line summarizing the negative slope. For network type, encode it as color on the scatter, or use small-multiple facets per network. This can reveal Simpson's paradox, where the pooled slope differs from within-group slopes. RED FLAG: Calling the correlation causal, or a bar chart that hides per-point structure.

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Visualizing a correlation with a third variable · Tezvyn