Conducted to define in detail the ingredients contributing to an effective classroom assessment environment, this study explored the assessment methods actually used by classroom teachers through case study observations and teacher journals. Chapter 1 provides an overview of the report. Chapter 2 presents the findings of a review of the literature on educational testing, teacher decision making, and the ethnographics of classroom assessment which formed the basis for the research design. (A seven page bibliography is appended to this chapter.) Chapter 3 presents three ethnographic studies (out of the 30 case studies conducted) of 6th grade classrooms in which researchers were participant observers for 20 days. Chapter 4 presents an analysis of assessment journals maintained by 32 elementary and secondary teachers over a 10-week period. Chapter 5 summarizes the findings. It concludes that while the assessment environment is under the direct control of the teacher, there are six sets of factors that constrain teachers in establishing that environment effectively: (1) teacher characteristics; (2)classroom characteristics; (3) school and district policy; (4) instructional materials available; (5) specific school subject characteristics; and (6) the actual assessments used. The specific ingredients of these constraining factors are listed along with the relevant underlying continuum and recommended observation strategies. (BS)