As the economies of nations compete for strong positions within a competitive global market place, many governments have become increasingly interested in the performance of all aspects of their education systems. This trend, coupled with the enormous expenditures that are devoted to education, has also precipitated widespread public requests for higher levels of scrutiny concerning the quality of education. These demands for information about school system performance can only be addressed through the implementation of systematic accountability systems. Historically, the education profession has conformed to the requirements of regulatory or compliance accountability systems (usually based on government statutes), and has also subscribed to professional norms established by associations of educators. However, at the beginning of the 21st Century, accountability systems have also been required to respond to demands that professional performance be judged by the results that have been achieved. This booklet offers a set of principles and strategies to be considered in the development and implementation of results-based accountability systems. Technical and political issues are addressed as well as the ways in which educators, policymakers, and community members can use the information from accountability systems to improve results. The statements presented here about accountability systems are likely to be generally applicable throughout the world. Even so, they should be assessed with reference to local conditions, and adapted accordingly. In any educational setting or cultural context, suggestions or guidelines for practice require sensitive and sensible application, and continuing evaluation.