[2] The scoring includes 22 variables covering the aspects of the patient's response to the inkblot.

[3] Holtzman and Swartz (1983) undertook a review of 25 years of research on the standardization of the HIT.

They reported that: 22 quantitative variables were developed covering most of the scoring categories and dimensions used with the Rorschach.

A large number of studies have confirmed the technique's differential validity, supported by findings from longitudinal, cross-sectional, and cross-cultural investigations.

Still other investigations of external validity have been conducted using physiological and behavioral measures as well as personality questionnaires.