sum of squares
sum of squares
Σ(xi – x̄)2,
where x̄ is the mean value of xi. For example, if an analysis yields a mean score of 5 but a person’s actual score is 7, the squared deviation for that individual is (7 − 5)2 = 22 = 4: This would be added to the squared deviations of all other individuals in the sample. Various types of sums of squares are calculated in analysis of variance, regression analysis, and other statistical procedures. See error sum of squares.