1. Evaluation of a psychiatric screening test, Cornell Word Form-1, was carried out in terms of the criterion: clinically evident psychiatric illness.2. At the more effective scoring level recommended (5, or more, significant responses), 53% of 337 known psychiatrically ill patients were correctly identified.3. At the same scoring level, 32% of 100 patients identified as presumably psychiatrically ill were found on psychiatric examination not to be so, i. e., were false positives.4. At scoring level 5, the test identified about 15% of, a university student sample as presumably psychiatrically ill; and in this agreed closely with similar and dissimilar tests applied to other university student populations.5. The significance of the regularities observed is not clear.6. The test missed 97% of psychiatrically ill medical students at scoring level 9, and 81% at scoring level 5.7. Routine medical examination by senior medical students and their instructors identified 20-30% medical clinic patients as presumably psychiatrically ill, with a probable minimum of 13% missed, and 6% false positives.Abstract Teaser