Abstract
Ronald K. Hambleton: A world-class psychometrician. This biographical sketch highlights Professor Hambleton's scientific and personal characteristics. His important scientific contributions are primarily in four areas: Item Response Theory and Applications, Criterion Referenced Assessment, the Translation and Adaptation of Educational and Psychological Tests, and Differential Item Functioning. What distinguishes Professor Hambleton's scientific work from many others is that he has established an international reputation in several psychometric topics. In the first three of his four priority areas, his research would place him among the top few researchers in the world. In fact, few psychometric topics have escaped his attention. Also, Professor Hambleton's research would be characterized as pioneering and with great depth. Furthermore, his work shows a balance between theory generation and advancement, and applications to solve practical problems. On a more personal note, his positive, open, reflective disposition, quick mind, and rounded personality have allowed him to perform at the highest level in his field in spite of day-to-day pressures and demands on his time for over 30 years. All of these characteristics contribute to making Professor Hambleton one of the most influential psychometricians of our time.
