Frederick J Gravetter is Professor Emeritus of Psychology at The College at Brockport, State University of New York College. While teaching at Brockport, he specialized in statistics, research design, and cognitive psychology. Dr. Gravetter received his Bachelor's degree in mathematics from M.I.T. and his Ph.D. in psychology from Duke University. In addition to publishing several research articles, Dr. Gravetter is co-author of the best-selling STATISTICS FOR THE BEHAVIORAL SCIENCES, 9th Edition, ESSENTIALS OF STATISTICS FOR THE BEHAVIORAL SCIENCES, 8th Edition, and (with Lori-Ann B. Forzano) RESEARCH METHODS FOR THE BEHAVIORAL SCIENCES, 5th Edition. Larry B. Wallnau is Professor Emeritus of Psychology at the State University of New York College at Brockport. The recipient of grants and awards in both research and teaching, Dr. Wallnau has published numerous research articles primarily on the effect of psychotropic drugs. With Frederick J Gravetter, he has co-authored previous editions of STATISTICS FOR THE BEHAVIORAL SCIENCES, now in its tenth edition, and ESSENTIALS OF STATISTICS FOR THE BEHAVIORAL SCIENCES, now in its eighth edition.