seniorProbability
What is the intuition behind variance decomposition?
Updated May 17, 2026
Short answer
Variance decomposition splits total variance into explained and unexplained components.
Deep explanation
Also known as ANOVA identity, Var(X)=E[Var(X|Y)] + Var(E[X|Y]). It separates variability due to randomness within groups and variability between group means, forming the basis of regression analysis.
Unlock with a Pro subscription to view this section.
View pricingReal-world example
No real-world example available yet.
Unlock with a Pro subscription to view this section.
Upgrade to ProCommon mistakes
No common mistakes listed yet.
Unlock with a Pro subscription to view this section.
Upgrade to ProFollow-up questions
No follow-up questions available yet.
Unlock with a Pro subscription to view this section.
Upgrade to Pro