The primary purpose of decision support systems (DSS) is to improve the quality of decisions. This paper suggests that improvement in decision quality is a function of the creation of new data and information applicable to the decision domain and the understanding and learning of that new knowledge by the decision maker; i.e., the purpose of decision support is knowledge creation. We propose an information system design theory for DSS as knowledge creation based on Nonaka?s knowledge spiral, including multiple kernel theories. These kernel theories and the associated process design methods are drawn from five distinct literatures: cognitive science, the theory of learning, artificial intelligence, knowledge management, and decision theory.