Aptitude and reading tests to be administered to technical college students are discussed in considering the design of a screening and diagnostic test battery. Diagnosis is condidered as a series of sequential steps: screening; testing; individualized program planning; program implementation; and investigation of the causes of reading difficulty. Reading skills necessary for successful functioning are discussed: comprehension in the context areas; vocabulary; comprehension; reading rate; and study skills. Test selection for inclusion in the test battery is based on the identification of the skills considered necessary for academic achievement. Guidelines for examining test characteristics are discussed: general nature of the test, such a kind of test, validity data, test forms, testing time, directions for administration; norm group; kinds of scores; and nature of the information provided by the test. To implement a diagnostic and screening program, three measures are recommended: (1) program coordination by a certified reading consultant; (2) an institutional commitment to the students who cannot attain acceptable skill development levels; and (3) resolution of such issues as administrative procedures, services offered, communication links, and evaluation methods and recordkeeping. A list of aptitude and reading tests is appended for potential inclusion in the battery. (MH)