The purpose of this book is to describe in nontechnical language the objectives, methods and findings of the six subject study conducted by the International Association for the Evaluation of Educational Achievement during the years 1966-1973. The six subjects covered in the study were Science, Reading Comprehension, Literature, English as a Foreign Language, French as a Foreign Language, and Civic Education. Separate volumes giving fuller information on each have been published. The present volume contains a summary of the information provided in these separate reports. In addition to chapters discussing factors associated with the six subjects, the book addresses a chapter to the origin and purpose of the study, the first steps of the study, the independent variables in the study, and the method of analysis. The final chapters deal with some of the more important findings of the study and the interpretation of national contrasts in school achievement. (DMT)