“…Unfortunately, drug outcome studies have typically failed to provide data on the relationship of the IMPS to other criterion measures (e.g., Goldberg, Mattson, Cole, & Klerman, 1967), or have reported limited validity data only in narrowly circulated government publications (Klett, 1961). Several studies (Lorr & Cave, 1966;Lorr, O'Connor, & Stafford, 1960;Mefferd, 1968) have found significant relationships between IMPS scores and scores on a ward rating scale-the Psychotic Reaction Profile (PRP) (Lorr et al, 1960); however, the latter relationships are partially confounded by considerable item overlap between the two scales. Only two studies to date have reported concurrent validity data on the IMPS with completely independent modes of assessment: Lorr and Hamlin (1971) found significant convergent correlations between the IMPS and several objective tests of psychomotor speed, vocabulary, etc., as well as the PRP; Paul et al (1972) found significant convergent correlations between the IMPS and itemindependent ward ratings and structured interview scores.…”