Presents an obituary for Robert M. Guion (1924-2012). Bob received his bachelor's degree from the University of Iowa in 1948 and his master's degree (1950) and doctorate (1952) from Purdue University, the latter in I-O psychology. His doctoral mentor, about whom he always spoke with gratitude, was C. H. Lawshe. Although Bob found employment opportunities limited on graduation, he knew that he wanted the freedom and independence of an academic position. He joined the faculty at Bowling Green State University (BGSU) in 1952. Bob served as chair of the department from 1966 to 1971 and edited the Journal of Applied Psychology from 1983 to 1988. He continued to rise through the professorial ranks and was ultimately named a Distinguished University Professor. In 1965, Bob won the James McKeen Cattell Award for research design from Division 14 (Society for Industrial and Organizational Psychology; SIOP) of the American Psychological Association (APA). He won it again in 1981. His landmark text Personnel Testing (1965, McGraw-Hill) was required reading for almost every I-O graduate student. In 1998 he published another classic, Assessment, Measurement, and Prediction for Personnel Decisions (Erlbaum). As an educator, Bob led the development of the master's and doctoral programs at BGSU and served as mentor for many of today's leaders in the field. As a contributor to professional psychology, he served as the president of two APA divisions, 14 and 5 (Evaluation, Measurement and Statistics), and also chaired APA's Board of Scientific Affairs. His career is a model of the blend of theory, research, and application. Bob was a model of integrity and deeply believed that the waste of human resources should pain the professional conscience of I-O psychologists. Bob worked tirelessly toward the development of a fundamental science that promotes human welfare at work.