This thesis investigates the relationship between semantic change and theory change in science. The study focuses on thirty years of developments in chaos theory. Because of measurement problems associated with certain nonlinear phenomena, the observability of chaotic systems is severely limited. In such cases, ongoing processes of language change may play a greater role in shaping scientific theories than in cases in which the phenomena are more easily observed. This study is interdisciplinary, drawing on theories from linguistics, philosophy, philology, and sociology. Several mechanisms of semantic change are explored in order to discover their possible influence on theory formation. Developments in chaos theory are described in terms of George Lakoff's radial model of conceptual categories. This model describes concepts in terms of (1) a central cluster which acts as a prototypical example, and (2) various non-central extensions from that center. I argue that in an emerging discipline, non-central extensions are made depending on the interests of the community. As Andrew Pickering observed, communities on the research front select a research direction that will intersect with the interests of more established research communities. This thesis explores several examples of historical developments in chaos research showing how conceptual change in science can be described in terms of Lakoff' s radial category model and Pickering's interest model. / Master of Science