My group's research activities are broad and multidisciplinary, and we are active participants in the network science, complex systems, computational biology, and computational social science communities. Our work generally focuses on understanding the mechanisms by which large-scale patterns emerge from the collective actions of heterogeneous individuals and on developing novel techniques for inferring such patterns and mechanisms from rich data sources. Much of this work is methdological in nature, and we actively develop novel statistical and computational methods for automatically analyzing and modeling complex phenomena in biological, social and technological systems. All of these efforts draw heavily on data analysis, machine learning, statistics, probability, algorithms and graph theory. We are particularly interested in interactions between theory and data, and the development of rigorous methods for the study of complex systems.
Three areas of current work are (i) the large-scale organization of complex networks, with particular emphasis on their modular or hierarchical structure; (ii) the mechanisms that shape the macroevolution of biological species across large spatial and temporal scales; and (iii) the political and physical processes that shape the large-scale dynamics of violent human conflicts, such as modern terrorism and warfare.