This paper considers the design and analysis of feeding back information about achievement test results to teachers and students in a high school classroom. An introductory section discusses the designing and administering of tests throughout the year in such a fashion as to provide pre-instruction, post-instruction, and retention achievement levels of groups of students in specific areas of the course. Three basic types of information are considered: feedback for individual students, feedback for homogeneous groups of students, and feedback for curriculum evaluation. The design of the formats of the output has evolved during the four years that the Comprehensive Achievement Monitoring (CAM) project has been in operation. Teachers' comments, as well as statistical analysis, has produced feedback information designed so that both teachers and students can dynamically make decisions concerning instructional activities. Data from several years of classroom monitoring in the subject areas of history and mathematics is presented. (Author)