The Teaching Gap, by James W. Stigler and James Hiebert, has served as a valuable resource for participants in the Adult Numeracy Study Circle, developed by TERC and piloted with ACLS staff. This book describes the research on how teachers in U. S. schools compare with those in other countries, especially since the Third International Mathematics and Science Study (TIMSS) revealed that U.S. students lag behind students from other countries. The ISBN for the book is 9781439143131.