ABSTRACT
When new curricula are developed and published, the claims that they will improve student achievement are typically based on market research and/ or the claims of the authors as a consequence of one or more trials of the materials in classrooms. The validity of such claims for diverse sites is often questionable. What is needed is a summative evaluation of any particular curriculum. This involves large-scale studies that gather data to determine if the newly created product is ready for large-scale use. They are expensive and difficult to carry out. Unfortunately, examples of such studies are rare.1
