This report describes the fifth in a series of investigations of the nature, role, and quality of teacher-developed classroom assessments. The purpose of this research program is to provide a clear picture of the assessment demands of the classroom so teacher educators can plan assessment training that is relevant to teachers' needs. The purpose of this particular study was to develop instrumentation for the observation and description of individual teachers' classroom assessment environments. Beginning with a general observational framework from a previous study, four researchers each observed and described two classroom assessment environments. Classrooms studied included high school mathematics, science, language arts, and social studies contexts. After completing observations and interviews with teachers and students, researchers revised the framework and prepared a profile of each classroom assessment environment. Each profile explores the teacher's reasons for assessment, the assessment methodology used, the factors considered by the teacher in selecting those methods, the quality of assessments, the teacher's use of feedback, the teacher's perceptions of students, and the effect of policy on classroom assessment. Based on a synthesis of profiles, generalizations are drawn about: (1) the nature, role, and quality of classroom assessment; and (2) teacher and principal assessment training needs. (Author/JAZ)