He also holds an Adjunct Professor position at the Graduate Institute of Biostatistics of China Medical University in Taichung, Taiwan. He began graduate work at the University of Chicago in 1988 and received his Ph.D. from the Committee on Research Methodology and Quantitative Psychology of the Department of Psychology in 1995. Dr. Chang is an internationally recognized psychometrician with pioneering expertise in applying item response theory to health-related quality of life and patient-reported outcomes measurement. He also has extensive experience in health information technology. His clinical infometrics discipline is to integrate informatics and psychometrics to improve the quality of care and patient safety.