The national study, sponsored by the National Institute of Juvenile Justice and Delinquency Prevention, will look at the implications of determinate and indeterminate sentencing for commitment and release decisionmaking for juvenile delinquents. This volume covering the study's first phase points out that recent literature criticizes indeterminate sentencing and an individualized, rehabilitation-oriented approach to corrections. Few works have addressed how determinate approaches could be or were being implemented in the juvenile justice system. To answer these questions, data were collected on the States' statutory approach to commitment and release. Administrative regulations were identified as were rules and written policies, and differing organizational approaches to release decisionmaking were analyzed. A primary method of data collection was a nationwide telephone survey of key juvenile justice agency personnel in each State. Researchers then developed a conceptual framework for analyzing commitment and release decisionmaking, based on the literature and on four social theories: systems, exchange, interactionist, and organizational. They suggest that decisionmaking systems have three properties -- structural, process, and decisionmaker characteristics -- and two contextual properties -other system and environmental influences. The report also contains a summary analysis of approaches to commitment and release decisionmaking across the country. Footnotes, tables, and 70 references are provided.