Lucy Cheser Jacobs has a B.S. in chemistry from Catharine Spalding College in Kentucky, and a M.S. and Ph.D. in educational psychology from Indiana University�Bloomington. She received a John H. Edwards fellowship during graduate study. Dr. Jacobs taught research methodology, statistics, measurement, and educational psychology courses at Indiana University. She served as Director of the Bureau of Evaluative Studies for several years, where she conducted institutional research studies. Before beginning graduate studies, she taught high school chemistry in Kentucky. She has co-authored INTRODUCTION TO RESEARCH IN EDUCATION (nine editions) and INTRODUCTION TO STATISTICS (both with D. Ary), and DEVELOPING AND USING TESTS EFFECTIVELY (with C. Chase). She held membership in AERA and NCME and presented papers at their annual conferences. In addition to co-authoring the first eight editions of INTRODUCTION TO RESEARCH IN EDUCATION, Donald Ary (B.S., M.S., Ph.D.) co-authored INTRODUCTION TO STATISTICS: PURPOSES AND PROCEDURES (with L. C. Jacobs), and ANALYZING QUANTITATIVE BEHAVIORAL OBSERVATION DATA (with H. K. Suen). He also co-authored the educational psychology text, READINGS IN CLASSROOM LEARNING AND PERCEPTION (with R. J. Mueller and E. C. McCormick). He wrote chapters for three books and published 35 journal articles, six of them in Behavioral Assessment. He presented papers at professional conferences, including the American Educational Research Association (AERA) and the Association for Behavioral Analysis. Dr. Ary taught research design, statistics, measurement, and educational psychology, first at Indiana University, then at Northern Illinois University, where he was director of the Educational Psychology and Special Education Research Office and interim chair of the Department of Educational Psychology, Counseling, and Special Education. He served as consultant to various educational offices in Illinois and to the Bureau of Elementary and Secondary Education, U.S. Office of Education. He also served on the editorial board of Research in Developmental Disabilities. Early in his career, Dr. Ary was an elementary teacher. Christine K. Sorensen Irvine (M.S., Ph.D., professional studies in education, Iowa State University) is a professor in Learning Design and Technology at the University of Hawaii at Manoa, where she teaches research methods courses in the doctoral program and mentors doctoral candidates. She also co-directs a U.S. Department of Education grant working with entities across the Pacific on educational program planning, evaluation, and assessment. She was Dean of the College of Education at the University of Hawaii from 2007 to 2012 and Dean of the College of Education at Northern Illinois University from 2001 to 2007. Dr. Sorensen has an extensive record in grants; her research areas have focused on technology integration in education. She has taught courses in research, evaluation, and higher education, and has expertise in both quantitative and qualitative methods of research. She has more than 30 publications, well over 100 presentations, and has chaired over 40 completed dissertations. She has co-authored INTRODUCTION TO RESEARCH IN EDUCATION since the seventh edition. David A. Walker (M.S., Ph.D., Iowa State University of Science and Technology), is a Professor of Educational Research, Technology, and Assessment and an Associate Dean for Academic Affairs at Northern Illinois University (NIU). Prior to NIU, he served on the faculty at Florida Atlantic University and was a post-doctorate researcher at Iowa State's Research Institute for Studies in Education. Dr. Walker has an extensive research record with 108 refereed publications, 30 technical and program reports, 146 refereed conference presentations, 40 invited presentations/lectures, and 215 statistical computer program creations. A majority of these scholarly works pertain to the themes of statistical methodology and/or research methods in areas such as effect sizes, reliability measures, and the general linear model. He has been involved in numerous federal and state-based grants, and as an evaluator in projects affiliated with teacher education. Dr. Walker has taught courses in research methods, assessment, testing, measurement, and statistics and has expertise in quantitative methods of research.