The Laboratory for Information and Decision Systems (LIDS) at the Massachusetts Institute of Technology (MIT) is hosting the Paths Ahead in the Science of Information and Decision Systems symposium on 12-14 Novemeber 2009 in Cambridge, MA.  The symposium brings together leading researchers from all around the world who have been influential in shaping the vision of and leading the field of information and decision systems. The Paths Ahead symposium will take a fresh look into old and new research directions, address the relevance, timing and interdisciplinary nature of such directions, and stimulate the preparation of position papers that highlight emerging paradigms in these research directions.  This gathering aims at articulating a picture of the challenges and ideas that will shape the future directions of research in the science of information and decision systems and foster systematic interactions of a broad community. The meeting will consist of several panel-oriented sessions which will focus on core disciplines, including Systems and Control; Networks and Networked Systems; Estimation, Inference and Learning; and Optimization and Decision Sciences, with considerable attention placed on challenges that cut across these disciplines.  In addition, the symposium will honor one of the major intellectual leaders of the field, Prof. Sanjoy Mitter, who officially retired in 2009.