SEVERAL OF THE ARTICLES DISCUSS THE RATIONALE FOR THE VIEW THAT COMMUNITY CONDITIONS MUST BE MODIFIED IN ANY EFFECTIVE PROGRAM OF TREATMENT AND PREVENTION AND THAT LOCAL COMMUNITIES MUST FIND METHODS OF INCORPORATING DELINQUENT YOUTH INTO THE CONSTRUCTIVE LIFE OF THE COMMUNITY. REFERENCE IS MADE TO STUDIES INDICATING THAT, WHERE THE VOLUME OF DELINQUENCY IS HIGH, CONDITIONS FAVORABLE TO THE MORAL, PHYSICAL, AND SOCIAL WELL-BEING OF CHILDREN ARE MISSING. SUCH STUDIES IMPLY THAT THE BEHAVIOR OF CHILDREN AND YOUTH, WHETHER DELINQUENT OR NONDELINQUENT, IS A REACTION TO THE CONDITIONS THEY ENCOUNTER IN THEIR FAMILIES AND IN THEIR COMMUNITIES. TEN OF THE ARTICLES CONSIDER SOCIAL FACTORS IN DELINQUENCY. OTHER ARTICLES INCLUDE A DISCUSSION OF DIFFERENTIAL ASSOCIATION AND CRIME PREVENTION AND THREE ASSESSMENTS OF THE CHICAGO AREA PROJECT, A COMMUNITY-BASED DELINQUENCY PREVENTION EFFORT BEGUN IN 1934.