Restriction of range is the term applied to the case in which observed sample data are not available across the entire range of interest. The most common case is that of a bivariate correlation between two normally distributed variables, one of which has a range less than that commonly observed in the population as a whole. In such cases the observed correlation in the range restricted sample [Page 1279]will be attenuated (lower) than it would be if data from the entire possible range were analyzed.

The context in which restriction of range is discussed most often is that of criterion-related validity evidence of predictors in a selection context such as employee selection or educational institution admissions. For instance, common cases include those in which job applicants ...