Beginning with a historical review of private correspondence schools, supervised high school level programs, military programs (notable the United States Armed Forces Institute), and activities by such university extension luminaries as William Rainey Harper and W. H. Lighty, this literature review covers accreditation and licensing problems, general characteristics of students, educational methods and course design, patterns of student achievement and completion, and innovations in correspondence methodology. Limitations affecting the effective use of correspondence study are assessed, along with the instructor role, steps in planning course content and materials, and the structuring of assignments and instructor response (feedback). Expected trends in the use of programed instruction, broadcast media, films and other audiovisual resources, small groups, special degree programs, and arrangements for course credits and degrees through examinations, are also suggested. Annotated chapter bibliographies contain 164 references. (LY)