Explained sum of squares - Wikipedia
en.wikipedia.org › wiki › Explained_sum_of_squaresIn statistics, the explained sum of squares ( ESS ), alternatively known as the model sum of squares or sum of squares due to regression ( SSR – not to be confused with the residual sum of squares (RSS) or sum of squares of errors), is a quantity used in describing how well a model, often a regression model, represents the data being modelled.