Val Tannen is a professor in the Department of Computer and Information Science of the University of Pennsylvania. He joined Penn after receiving his PhD from the Massachusetts Institute of Technology in 1987. He worked for a time in Programming Languages, and his current research interests are in Databases. He has always been interested in applications of Logic to Computer Science and since 1994 he has also worked in Bioinformatics, leading a number of interdisciplinary projects. In Databases, he and his students and collaborators have worked on query language design and on models and systems for query optimization, parallel query processing, and data integration. More recently their work has focused on models and systems for data sharing, data provenance, the management of uncertain information and algorithmic provisioning for what-if analysis. Tannen is an ACM Fellow.