Human cognitive system and information processing theories were used as the theoretical base that frames an interpretation of adult literacy research from World War I (WWI) through 1993. These theoretical perspectives are as follows: (1) literacy learning is grounded in a distinct developmental sequence; and (2) literacy learning is dependent on listening skills and experience, literacy opportunities and practice, and the general body of knowledge created through these experiences. The military origins of intelligence assessment include the WWI Alpha and Beta tests, Army General Classification Test of WWII, Armed Forces Qualification Test, and Armed Services Vocational Aptitude Battery. National civilian studies of literacy assessment differ from the military tests primarily in design. Civilian tests focus on use of "real-world" test items and open-ended questions rather than multiple-choice items. Results of civilian studies show the same strong trends evident through the military studies: individuals with more formal education read more and have higher test scores; individuals with more education are more likely to read and to read a variety of materials; and whites outperform Hispanics and Hispanics outperform African-Americans overall. In general, findings indicate the following: listening skills are higher than reading skills; intergenerational literacy is another important facet of increasing literacy for individuals throughout society; and literacy level affects job status. (YLB)