SAMSI is a national institute that will deeply impact the futureof the statistical and mathematical sciences and, through them,science in general, by catalyzing creation of the theory andmethodology necessary to confront the central data- andmodel-driven scientific challenges of our time. SAMSI will focuson new syntheses of the statistical sciences, applied mathematicsand disciplinary science. To illustrate the vision, consider anactivity central to modern science and technology, and with whichSAMSI will be heavily engaged: numerical modeling of complexphysical processes. Developing numerical models and evaluatingtheir fidelity to reality requires merging knowledge frommultiple disciplines. Applied mathematics builds on disciplinaryunderstanding to construct a fine-detail numerical representationof the deterministic aspects of a process; probability providesconcepts and insight to characterize stochastic elements of theprocess; and statistics provides the mechanisms to relate theseconstructs to observational data on the real-world process. But,despite a multiplicity of context-specific advances, there iscurrently no general framework for combining these disciplines,much less a formal system for simultaneously applying them. TheSAMSI efforts in this direction will focus on filling this gap,by bringing together statisticians, mathematicians and modelersfrom across the country (and beyond) to establish frameworks formodel development and validation, at a high level that spansmultiple application contexts.To carry out this synthesis of the statistical sciences, appliedmathematical sciences and disciplinary sciences, SAMSI engagesestablished researchers - from academia, industry, nationallaboratories and government - as well as young researchers(postdoctoral fellows and graduate students) at the formativestages of their careers. Each research program lasts from 6months to one year, and involves a host of activities rangingfrom research by intensive interdisciplinary working groups tobroad, energizing workshops. Outreach to undergraduate students,high-school teachers and faculty from teaching institutionsextends SAMSI's impact on the essential development of thenational human resource base for science. To enable activities ofthe breadth and depth necessary for the success of SAMSI, theinstitute is a partnership between the National ScienceFoundation and the consortium of Duke University, North CarolinaState University, the University of North Carolina at Chapel Hilland the National Institute of Statistical Sciences. Thesepartners provide a uniquely strong base for SAMSI's nationalscope. Scientific input to SAMSI comes, in part, from a NationalAdvisory Council composed of eminent statistical and mathematicalscientists. Most important, SAMSI will engage the entirenationwide statistical and mathematical sciences communities, bymeans of widely publicized opportunities to bring problems toSAMSI, or direct SAMSI's attention to them.