Dr. Patrick H. Worley is a senior research computer scientist in the Computer Science and Mathematics Division of Oak Ridge National Laboratory (ORNL). He earned his Ph.D. in Computer Science from Stanford University in 1988. His research interests include parallel algorithm design and implementation, the performance evaluation and optimization of parallel scientific programs, and the numerical simulation of PDEs. Worley currently leads ORNL's participation in the Department of Energy (DOE) SciDAC project in performance evaluation (PERC), with primary responsibility for PERC's engagement with the SciDAC science application projects. He is also a lead performance engineer for the National Science Foundation and DOE Community Climate System Model (CCSM), the principal investigator for the Performance Evaluation and Analysis Consortium End Station at the National Center for Computational Sciences Leadership Computing Facility, and a co-chair of the Software Engineering Working Group for the CCSM.