ORDINARY LEAST SQUARES (OLS)

(Statistics) Mathematical procedures for attributing the variability of one quantity to changes in one or more other quantities. Often called "line fitting" or "curve fitting" since it produces an equation that can be used to predict the quantity of interest under many conditions. The concept is to attempt to fit a mathematical function to a series of data whereby the square of the error terms measuring the differences between the model estimates and actual observations is minimized, hence the term Ordinary Least Squares (OLS) is also used to describe this process. The standard of regression model is generally termed the Classical Linear Regression (CLR) Model. Also see Regression Analysis.