Correlation and Linear Regression

Abstract

The purpose of this lesson on correlation and linear regression is to provide guidance on how R can be used to determine the association between two variables and to then use this degree of association to predict future outcomes. Past behavior is the best predictor of future behavior. This concept applies in the biological sciences, physical sciences, social sciences, and also in economics. By knowing past relationships between variables (e.g., correlation), it is then possible to build a prediction equation to foretell future values for selected variables (e.g., regression). This lesson will focus on Pearson’s Product Moment Coefficient of Correlation (Pearson’s r, perhaps the most common test for determining if there is an association between phenomena) and linear regression.