Abstract
Robert Joseph Mislevy (known to friends and colleagues as Bob) was born June 28, 1950, and passed away at the age of 74 in Severna Park, Maryland, USA on May 22, 2025, with his daughters by his side. In his career, Bob had tremendous impact on research, practice, and philosophy. He was a past-president of the Psychometric Society, an elected member of the National Academy of Education, an elected fellow of the American Educational Research Association, and served on National Academies of Science committees concerning assessment, instruction, and psychology. Among other honors, he received the Award for Significant Contribution to Educational Measurement and Research Methodology from the American Educational Research Association, the E.F. Lindquist Award from the American Educational Research Association and ACT, the National Council on Measurement in Education’s Award for Exceptional Achievement in Educational Measurement (five times), and awards for career and lifetime contributions from the Psychometric Society and the National Council on Measurement in Education.