The Santa Fe Institute (SFI) is an independent, nonprofit theoretical research institute located in Santa Fe (New Mexico, United States) and dedicated to the multidisciplinary study of the fundamental principles of complex adaptive systems, including physical, computational, biological, and social systems. The Institute is ranked 25th among the world's "Top Science and Technology Think Tanks" and 25th among the world's "Best Transdisciplinary Research Think Tanks" according to the 2018 edition of the Global Go To Think Tank Index Reports, published annually by the University of Pennsylvania.[1]