The Ordinary Least Squares tool or OLS is a linear regression tool used to generate predictions or model a dependent variable in terms of its relationships to a set of explanatory variables. OLS is the best known regression technique and provides a good starting point for spatial regression analysis. This tool provides a global model of a variable or process you are trying to understand or predict. The result is a single regression equation that depicts a positive or negative linear relationship.

OLS is almost always an iterative process, so don't expect to simply run this tool once and be done. It's very challenging, especially in the social sciences, to find the correct explanatory variables for a dependent variable. In addition to spending many hours of research in identifying potential explanatory variables, you will, in most cases, need to run the OLS tool many times, examine the results, and perform your checks. At some point...