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sum of squares

(symbol: SS) the number obtained by determining the deviation of each point in a data set from some value (such as a mean or predicted value), multiplying each deviation by itself, and adding the resulting products. Thus, for a set of variables xi,
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.

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Psychology term of the day

January 31st 2025

centralist psychology

centralist psychology

1. a psychological approach that focuses on behavior as a function of the higher brain centers, as opposed to peripheralist psychology (see peripheralism), which focuses on the effects of the receptors, glands, and muscles on behavior. Centralist psychology is essentially equivalent to centralism.

2. more generally, the idea that mental activity or mind occurs in or is a function of the brain alone.