Coefficient of Determination R Squared

The Coefficient of Determination (also known as R-Squared, where R is the Correlation Coefficient), has a range of 0 to 1. It measures that part of the variance of the response that is explained by the Regression Function . For example, a COD if .70 implies that 70% of the variation in y is accounted for by the Regression Equation. Most statisticians consider a COD of .7 or higher for a reasonable model.

R2 = 1 - (SSE/TSS)    

SSE - Sum of squares of the error; TSS - Total Sum of Squares

Regressions with many parameters and few data often have high values of R-squared. In these cases, the Corrected Coefficient of Determination is preferred.

Learn more about the Regression tools in Six Sigma Demystified (2011, McGraw-Hill) by Paul Keller, in his online Regression short course (only $99), or his online Black Belt certification training course ($875).