association (statistics)

In statistics, an association is any relationship between two measured quantities that renders them statistically dependent. The term "association" is closely related to the term "correlation." Both terms imply that two or more variables vary according to some pattern. However, correlation is more rigidly defined by some correlation coefficient which measures the degree to which the association of the variables tends to a certain pattern. Sometimes the pattern of association is a simple linear relationship (as in the case of the popular Pearson product moment correlation coefficient (commonly called simply "the correlation coefficient"), although other forms of correlation are better suited to non-linear associations.