The purpose of this book is to present an account of several different studies of the relationship of food additives to child behavior and learn­ ing problems. Because the outcome of these studies has deep, personal interest for many parents and their children, I have tried to present the studies in such a way that the logic and evidence of the studies is com­ prehensible to informed adults interested in weighing the facts for themselves. Unfortunately, the facts do not always follow a straightfor­ ward course. Part of my purpose has been to show the complexities lying in the way of the answers to apparently simple questions. I believe it is healthy and important for parents to examine the scientific evidence on issues affecting their daily lives, and to become aware of the process of research surrounding controversial claims regarding new therapies. New ideas in behavioral science are often difficult to track down and evaluate, and consequently there may be a large gap between therapeu­ tic claims and evidence bearing on those claims. The mother who won­ ders whether her child should be treated with a special diet is unlikely to have the facts necessary to make a judgment of the costs and benefits. She should however, know some of the major pitfalls in coming to a conclusion for or against such a course.