Defining assessment in the widest possible way, this work is a comprehensive ethnographic study of assessment. The case studies cover most of the important questions concerning assessment: who is being assessed and who is doing the assessing?; what is being assessed and when and where is the assessment taking place?; how does assessment function and how are assessment findings interpreted? The findings have major implications for education practice and policy. It shows how supposedly objective assessment procedures depend on their contexts and are vulnerable to both bias and distortion. The study provides the definitive examination of assessment in the 5-11 ranges.