APA Dictionary of Psychology

the proportion of the variance in a dependent variable that can be determined or explained by one or more other variables. In analysis of variance procedures, the explained variance usually is given by eta squared or omega squared, whereas in prediction methods, such as multiple regression, it usually is given by the coefficient of multiple determination. Explained variance also is applied in procedures such as principal components analysis or factor analysis to describe the proportion of the variance in a measure that can be understood or predicted from a component or factor. Compare error variance.