The guide was developed by the Health Careers Opportunity Program, the principal Federal program focused on increasing the numbers of disadvantaged individuals who train for and enter the health professions. The guide is intended to help institutional grantees working with such students in the areas of: (1) diagnostic testing in cognitive and psychosocial processes, (2) diagnostic testing to determine student strengths and weaknesses in test-taking skills, (3) admission tests, and (4) credentialing tests. The publication summarizes 41 tests and is divided into three sections--diagnostic tests (10), admission tests (12), and credentialing examinations (19). For each test the following information is usually provided: purpose or use of the test; educational level or levels the test is appropriate for; a description of the areas assessed by the instrument; test format; time factors; type of scoring and how scores are used; dates of national examinations; and name, address, and telephone number of the source of the test. (DB)