It is the authors hope that the science education community will use the results of the Third International Mathematics and Science Study (TIMSS) to explore current issues in science education. Among these issues are the balance between breadth and depth, the rigor of our science curriculum, and the applicability of the secondary school science curricula of other nations . . . as useful models for the U.S. science curriculum, which is more typically stop-and-go. This article was first published in January, 1999.