David R. Krathwohl is Hannah Hammond Professor of Education Emeritus, School of Education, Syracuse University. He is the author of Methods of Educational and Social Science Research: An Integrated Approach (2nd ed.) and Bloom's Taxonomy of Educational Objectives: Cognitive Domain, as well as coeditor with Lorin Anderson of A Taxonomy for Learning, Teaching, and Assessing: A Revision of Bloom's Taxonomy of Educational Objectives.

Nick L. Smith is currently Professor of Education, School of Education, Syracuse University, and previously held positions at the University of Nebraska Medical Center and the Northwest Regional Educational Laboratory. He is author or coauthor of more than fifty refereed articles and editor or coeditor of eight volumes, including Varieties of Investigative Evaluation.