Adult illiteracy is a complex, costly, and growing social problem. Three common areas of controversy related to the problem are: (1) definitions of adult literacy, (2) characteristics of illiterate adults, and (3) the purposes of literacy education. Illiteracy can be understood only in relation to a culture's definition of literacy. Due to differing definitions, statistics on the extent of illiteracy vary widely. The concept of "functional literacy" is controversial because it is determined by external standards and criteria. A tone of mission and concern for the less fortunate has dominated the perspective of illiterate adults. A picture is emerging now of illiterate adults as individuals who have educated themselves through life experiences and are frustrated with present literacy programs. Two common models of literacy programs are personal development and improvement and social change. Two primary systems for literacy programs currently serve the individual--the federally funded adult basic education program and national volunteer literacy efforts. Employers are emerging as a third delivery system providing literacy training for individual development. Community-controlled agencies that also offer literacy education are committed to improvement. (YLB)