While the law governing the definition of educational adequacy is still evolving, partial definitions can be gleaned from various state and federal laws and regulations prescribing standards for schools and from judicial interpretations of constitutional and statutory provisions. This document presents the results of such an analysis. After delineating the research questions and procedures guiding the study, and the definitional distinctions between the closely related concepts involved, the report examines relevant litigation. The cases reviewed affect state school finance schemes, the rights of students with special needs, and parental control over educational choices. State legislative and regulatory activity defining adequacy and establishing adequacy standards is described next. The nature of school funding laws, eight states' statutory definitions of adequacy, and the application of program requirements, accountability mandates, and minimum competency standards are covered. The federal role in defining and establishing adequacy standards is addressed last, with special attention paid to regulations regarding handicapped students, bilingual, compensatory, and vocational education, and research, development, and dissemination activities. A final chapter summarizes the findings, discusses obstacles to defining adequacy conclusively, and comments on prospects for the 1980s. Appendices list relevant court cases and pinpoint pertinent provisions of state constitutions. (Author/PGD)