This study investigated changes in test performance of disadvantaged people as a result of literacy training. Differences between scores obtained before and after basic literacy training were obtained. The study also investigated predictors of achievement-test-score improvement. Standardized achievement tests of vocabulary, reading comprehension, arithmetic computation, and arithmetic reasoning were administered in 16 states. Raw scores were converted to grade score units and five derived scores were computed. The General Aptitude Test Battery (GATB) tests were also administered. Mean achievement test improvement was approximately nine grade scores or one grade equivalent for a mean of 208 hours of training. Initial reading achievement, minority group status, GATB aptitudes, and nonreading test performance predicted arithmetic improvement. In general, the same variables did not predict or were not as predictive of reading achievement improvement. (Author)