Which goals and standards guide science education across the world? This first report of the Third International Mathematics and Science Study (TIMSS) explores this question by examining data collected in the TIMSS Curriculum Analysis. This study includes an exhaustive, page-by-page inventory of science content and other pedagogical characteristics collected from hundreds of textbooks and curriculum guides from almost 50 countries. These data document many important features of these countries’ mathematics education curricula. It examines important features of curriculum policy across the TIMSS countries, especially the role of textbooks and curriculum guides. It also portrays similarities and differences in science curricula in the succession of objectives across grades. Additionally, it details characteristics of the science curriculum as embodied in textbooks and curriculum guides intended for select grades. Th book should be of interest to anyone concerned with science education standards, curriculum policy, cross-national educational comparisons, and science pedagogy.