This booklet examines high-profile issues and major questions involved in international educational achievement studies. Some of these questions, which education activists and the public most often ask, are as follows: What benefits do international studies of achievement have for development of curricula in countries participating in this study? To what extent can the operation of a national system of curriculum (versus a state curriculum or school district curriculum or school-based curriculum) be assessed in an international study? If a comparison of subgroups of students within a country is to be undertaken, what are the subgroups that should be compared and why? Conceptualization and conduct of international studies are not an easy matter, but if they are well done, they can be of great benefit to national policymakers in education. Appendix 1 gives a brief description of the studies mentioned in this report. Appendix 2 alerts readers to the kinds of questions they should be asking when reading the reports of studies on international educational achievement. (Contains 47 references.) (RT)