What does the Pearson product moment correlation measure?

The Pearson product moment correlation is a statistical measure that specifically assesses the strength and direction of the linear relationship between two continuous variables. It produces a correlation coefficient that ranges from -1 to 1. A coefficient close to 1 indicates a strong positive relationship, where as one close to -1 indicates a strong negative relationship. A value around 0 suggests little to no linear relationship.

This measurement is crucial in psychology for understanding how variables are related to one another, allowing researchers to make predictions and draw inferences about the data being studied. The other options pertain to different statistical concepts; calculating an average, measuring variability, and identifying the mode do not evaluate the relationship between two variables, which is the essence of what the Pearson product moment correlation aims to do.