Testing includes all the things teachers do to assess the learning progress of their students and to diagnose their learning difficulties. Most teachers can develop whatever tools they need to assess student progress, but, if teachers are to test rigorously and frequently, they must be given adequate time to evaluate students individually, adequate resources to assess student progress fairly, and the support of specialists to help diagnose particularly complex student learning disabilities. External evaluations are of little help; testing and assessment processes must be an integral part of the curriculum and instructional process. In addition to testing to improve classroom instruction, testing has other legitimate purposes, such as providing information to policy makers, parents, and the news media. (RH)