Characterizing Pedagogical Flow presents conclusions from a multi-disciplinary, national research project blending quantitative and qualitative methodologies. The project investigated the mathematics and science curriculum, teaching, and classroom practices in six countries. Focusing on classrooms for nine- and thirteen-year olds, this project culminated in the student, teacher, and school background questionnaires used in the recently conducted Third International Mathematics and Science Study (TIMSS) sponsored by the International Association for the Evaluation of Educational Achievement (IEA). The work produced portraits of mathematics and science education that were dramatically different for each of the countries involved: France, Japan, Norway, Spain, Switzerland, and the United States. It is proposed that these differences may be explained by the interaction of curriculum and pedagogy in a culturally unique manner which yields classroom learning experiences that are qualitatively different from country to country. This idea has profound implications for how international education research is interpreted. The implications and recommendations discussed will be of interest to researchers as well as to the policy makers who make use of international education research