unforced intercept. History The creation of the coefficient of determination has been attributed to the geneticist Sewall Wright and was first published in 1921. See also Anscombe's quartet Fraction of variance unexplained Goodness of fit Nash–Sutcliffe model efficiency coefficient (hydrological applications) Pearson product-moment correlation coefficient Proportional reduction in loss Regression model validation Root mean square deviation Stepwise regression Notes Further reading Regression diagnostics Statistical ratios Least squares