APA Dictionary of Psychology

a type of regression analysis in which the researcher strives to develop a least-squared-errors solution or least squares solution to describe the relationship between an outcome or dependent variable and one or more predictors or independent variables. That is, one develops a model that is the best fit for the data because it yields the smallest squared differences between the actual observations and their values as predicted by the model. Also called least squares estimation; ordinary least squares (OLS) regression. See least squares criterion.