What is covariance and how is it different from correlation?

Updated May 17, 2026

Short answer

Covariance measures directional relationship; correlation measures standardized strength of relationship.

Deep explanation

Covariance depends on scale and units, making interpretation difficult across datasets. Correlation normalizes covariance by dividing by standard deviations, producing a bounded value between -1 and 1, allowing comparison across variables.

Real-world example

Covariance between rainfall and crop yield; correlation helps compare across regions.

Common mistakes

  • Assuming covariance magnitude is comparable across datasets.

Follow-up questions

  • Can covariance be zero but correlation non-zero?
  • Why is correlation bounded?

More Probability interview questions

View all →