The 1990 report on student charges at public colleges and universities describes the costs of attending about 90 percent of the national publicly assisted, four-year institutions. The report uses data compiled by the American Association of State Colleges and Universities (AASCU) and the National Association of State Universities and Land-Grand Colleges (NASULGC). The report covers issues including 2-year comparisons of average undergraduate charges; average room and board costs; and average charges for graduate students and students in first professional schools of law, medicine, dentistry, and veterinary medicine. It also examines current theories among educators and economists about the cause of rising tuition and predications for future trends. For the fourth consecutive year, the most often-cited reason for increases in student charges was faculty salary increases with the following other factors cited in descending order: equipment and facilities replacement and repair, legislative action affecting the relationship between tuition and cost; and decreasing appropriations. Review of recent analysis of rising costs notes attempts to redirect attentions to consideration of enrollment trends and expenditures and economic trends as important factors. Extensive appendices present data tables including cost information for specific colleges and universities. (JB)