interclass correlation
the degree of bivariate relationship between two variables from different measurement classes (i.e., the variables have distinct metrics and variances). For example, one may use an interclass correlation to determine the relation of IQ points (a class of measurement representing aptitude) to grade point averages (a class of measurement representing achievement), or the relation of length (e.g., inches) to weight (e.g., pounds). Currently, the only interclass correlation in common use is the Pearson product-moment correlation coefficient. Compare intraclass correlation.