Pearson’s correlation: The bivariate statistical analysis used when both independent and dependent variables are continuous.
The question asked in a correlation analysis is, “When the IV increases by one unit, what happens to the DV?” The DV might increase (a positive correlation), it might decrease (a negative correlation), or it might do nothing at all (no correlation). Figure 13.1 depicts these possibilities.
Positive correlation: When a one-unit increase in the independent variable is associated with an increase in the dependent variable.
Negative correlation: When a one-unit increase in the independent variable is associated with a decrease in the dependent variable.
This technique is Pearson’s correlation (sometimes also called Pearson’s r) , because it was developed by Karl Pearson, who was instrumental in advancing the field of statistics.