author bio: David Klein had retired as Professor of Social Sciences from Michigan State University, where he taught much of the material in this book. Marymae Klein was a college reference librarian who devoted much of her time to helping students find authoritative source materials for their various assignments. The Kleins, who have written a number of books for young readers, now live in Seattle. Book Reviews: "Certainly an eye-opening and thought-provoking introduction to how to use one抯 power of reason in discriminating sense from nonsense." Booklist "This is a well-written, interesting, easy-to-read book. I recommend it for middle-school students and adults." Science Teacher, February 1986 "An articulate introduction to the art of logical thinking匰tressing at all times the value of a questioning mind, the authors cannily use statistical subjects that are of interest to young people, such as the accident rates of teenage drivers 匛venhanded in its treatment of issues, the book is outstanding in its clarity, sometimes surprising in its conclusions, and fascinating." The Horn Book How Do You Know It抯 True? has joined my short list of hallmark children抯 literature titles." Linda Winkler, St. Petersburg Times