L.J. Wei’s research is in the area of developing statistical methods for the design and analysis of clinical trials. In 1977-78 he introduced the “urn design” for two-arm sequential clinical studies. Dr. Wei has also worked to develop numerous methods for analyzing data with multiple outcome or repeated measurements obtained from study subjects. Dr. Wei is currently a senior statistician at the Statistical and Data Analysis Center. He works closely with the medical investigators in Pediatrics AIDS clinical trials for evaluating new treatments for HIV patients.