VITTORIO CASTELLI received his MS in both statistics and electrical engineering and his PhD in electrical engineering from Stanford University. He currently works at the IBM Thomas J. Watson Research Center, where his main research interests include information theory, statistics, classification, and their applications to performance analysis and computer architecture. LAWRENCE D. BERGMAN received his PhD in Computer Science from the University of North Carolina at Chapel Hill, and currently works at the IBM Thomas J. Watson Research Center. His research interests include user-interfaces a...