Research in this area focuses on developing more effective methods for humans to interact with and use computer technology. HCI draws from computer science, sociology, and psychology to create better interfaces, to improve human-human interactions, and to tailor computer technology to the needs of an individual or organization. The department's HCI group specializes in interfaces that help groups of people work together more effectively. Research efforts include developing algorithms and interfaces for handheld devices to aid coordination in space and time, and in applying social science theories from economics and social psychology to the development of community Web sites. The group also specializes in recommender systems with a long history in the development and analysis of algorithms, interfaces, and user applications.