Description of Statistical Sidebar: Causation and Pearson''s Correlation Coefficient
Correlation is a statistical measure of how closely two variables are related. There could either be a positive (as one goes up, the other goes up) or a negative (as one goes up, the other goes down) correlation. The degree of correlation can be weak or strong. One of the most commonly used correlation statistics is the Pearson Product Moment Correlation or Pearson Correlation, for short. This statistic is calculated using an equation that relates two sets of scores for two different measures. The equation results in a single number called the correlation coefficient and designated by the letter “r”. The formula for r is available in Figure 1.