Correlation Analysis
Pearson's product moment correlation coefficient


Correlation coefficient definition

Pearson's correlation coefficient (r), expresses the degree of linear relationship between two variables measured from the same individual. Pearson's r values can range between -1.00 to +1.00.  A correlation coefficient of +1.00 signifies a perfect positive relationship, while -1.00 shows a perfect negative relationship.  The smallest correlation is zero. 

Correlation coefficient formula

One formula for Pearson's r equation is: r = Sum(ZxZy) / N which indicates that Pearson's r is equal to the average crossproduct of the variables in standardized form.

Correlation significance

Pearson's r can be assessed for significance using a standard F test.