This booklet is planned to help teachers, parents, students, and community members to understand concepts and research relating to testing in public schools. Three general uses--public access, accountability, and standards--relate to testing in its broadest conception. The major purposes of tests are discussed, as are some different types of tests, the criterion-referenced test, features of tests such as validity, standards, reliability, and bias, and the usefulness of tests. Four principles are illustrated which, if employed as a basis for the review of a testing process, could result in significant changes in the way people think about tests and believe in their usefulness. These principles state that tests should be public, economical, related to instruction, and should offer significant experiences to students. (Author/GK)