statistics - a branch of applied mathematics concerned with the collection and interpretation of quantitative data and the use of probability theory to estimate population parameters

distribution free statistic, nonparametric statistic - a statistic computed without knowledge of the form or the parameters of the distribution from which observations are drawn

Kendall partial rank correlation - a nonparametric measure of partial correlation

coefficient of concordance - a coefficient of agreement (concordance) between different sets of rank orderings of the same set of things

Kendall rank correlation, Kendall's tau, tau coefficient of correlation - a nonparametric measure of the agreement between two rankings