EFFECTIVE SCHOOL IMPROVEMENT DEPENDS UPON AN ANALYSIS OF SCHOOLS AS SOCIAL SYSTEMS AND THE DETERMINATION OF THOSE STRUCTURES AND PROCESSES MOST PROMISING AS ENTRY POINTS FOR CHANGE EFFORTS. FIVE FEATURES ARE CENTRAL TO THE AMERICAN PUBLIC SCHOOL--ITS CHILDREN-CHANGING EMPHASIS, LOCAL CONTROL, NONVOLUNTARY NATURE, RELATIVE ISOLATION FROM OTHER SOCIALIZING AGENCIES IN THE LOCAL COMMUNITY, AND COMPLEX LINKAGE WITH OTHER INSTITUTIONS AND ORGANIZATIONS IN THE LARGER SOCIETY. FOUR ESSENTIAL PROPERTIES OF SCHOOLS AS SYSTEMS INCLUDE--(1) DIVERSITY AND CONFLICT IN GOAL SPECIFICATION, (2) MECHANISMS FOR TASK ACCOMPLISHMENT, (3) INTERNAL INTEGRATION, COORDINATION, AND INTERDEPENDENCE, AND (4) MUTUAL ADAPTATION OF SCHOOL AND COMMUNITY. PROBLEMS RELATED TO EACH OF THESE PROPERTIES ARE SYMPTOMATIC OF THE SCHOOL IN INTERACTION WITH CURRENT DEMANDS. IMPLICATIONS OF THE ANALYSIS FOR RESEARCH AND ACTION INCLUDE THE RECOGNITION OF SCHOOL SYSTEM PROPERTIES HAVING CURRENT UTILITY, FOCUS OF EFFORTS ON MODIFYING ESSENTIAL PROPERTIES RATHER THAN ATTACKING SYMPTOMS, CAREFUL ATTENTION TO THE GAINING OF SANCTIONS FOR CHANGE AGENT RECOMMENDATIONS, DETERMINATION OF THE CLIENT SYSTEM WITH WHICH THE CHANGE AGENT IS WORKING, AND FORMULATION OF MAJOR CHANGE GOALS FOR SCHOOL SYSTEMS AND STRATEGIES FOR THE ACCOMPLISHMENT OF CHANGE. THIRTEEN MECHANISMS ARE SUGGESTED FOR CORRECTING DYSFUNCTIONAL ASPECTS OF SCHOOLS. THIS ARTICLE WAS PUBLISHED IN "CHANGE IN SCHOOL SYSTEMS," AVAILABLE FROM THE NATIONAL TRAINING LABORATORIES, NATIONAL EDUCATION ASSOCIATION, 1201 16TH STREET, N.W., WASHINGTON, D.C. 20036, FOR $2.50. (JK)