A conceptualization of educational indicator systems is presented, and their guiding principles and criteria are outlined. Three developmental projects are described that represent the indicator systems that promise to provide an explanatory framework for education. An indicator system should be perceived as an integrated whole in which the various aspects function as a system. Multiple indicators are needed to reflect the complexities of education. Any indicator system should be based on the goals, priorities, and expectations of its originating group, whether local, provincial, national, or international. The three examples that illustrate a broad perspective on indicator systems that attempt to embed student outcomes in the context of the educational system are: (1) the International Educational Indicators Project focusing on Australia, the United States, France, Austria, the Netherlands, and Canada; (2) the Council of Ministers of Education, Canada School Achievement Indicators Project; and (3) the Educational Quality Indicators Project of Alberta (Canada). These examples illustrate the importance of involving the stakeholders in the establishment of an effective and integrated system of indicators. A 79-item list of references is included. (SLD)