districts across the country, they typically do not span all the years of pre-college education and can lack coherence. Rather, local school districts as well as entities that can influence them, such as textbook companies, national curriculum development groups, and state educational agencies, tend to organize instruction around smaller "chunks" of schooling that may focus on the primary years (grades K-2), on grades 6-8, or on a particular highschool-level course. These smaller chunks of schooling are not necessarily designed to maximize the opportunities for all students to learn the content called for in standards. By contrast, this report emphasizes the importance of defining and coordinating curricula across the entire 13-year span — based on standards in use by local school districts — as a way to improve the quality of education. It describes the components of coherent curriculum programs based on mathematics or science standards or both and a process for designing such programs.4 Through the process, schools and school districts will be able to develop greater alignment between existing curriculum programs and content standards. In many districts, curriculum program design committees will be formed to perform the task.
The Third International Mathematics and Science Study (TIMSS) compared the achievement of over 500,000 fourth-, eighth-, and twelfth-grade students in 41 countries. In addition to measuring achievement in mathematics and science, TIMSS measured the opportunities of students to learn mathematics and science. The data were obtained through classroom observations, videotaping of classroom teaching, teacher and student surveys, and an extensive review of each country's curricula. The results of the study indicated that the typical mathematics and science curricula in United States school systems are not well designed.
When fourth-grade student achievement data from TIMSS were analyzed, only one other country's students outperformed U.S. students in science. U.S. students also were above the international average in mathematics. However, when eighth-grade student