A logically sound and methodologically easy technique for improving the construct validity of instruments and developed for relatively new concepts is described. It is based on the premise that if an instrument is valid, so should be each item within it and, therefore, the latter should sustain in field setting the behavioral implications derived from the theory underlying the construct. This idea was examined for 87 items of seven factorially "pure" scales, using a nearly random sample of about 7,000 subjects, and testing 10 such hypotheses for each item. The results are described. (Author/BB)