A fundamental process in many important research foci in information systems is the appropriation of IT artifacts in creative ways by users. The objective of this thesis is to develop a theoretical explanation of that process. An embedded multiple-case study of incidents in which users, in a variety of field settings, developed creative ways to apply IT artifacts, was conducted. Employing theoretical lenses drawn from cognitive science (dual-process theory, distributed cognition), and Markus and Silver’s (2008) variant of adaptive structuration theory, a novel theoretical framework was developed to analyze the data. This framework – Affordance Field Theory – was used to abstract away the context-specific details of each case, so that the events in each could be compared and analyzed using a common conceptual vocabulary. Applying critical realist assumptions, the initial retroductive analysis was done with narrative networks, then the cases were re-analyzed using framework matrices. The complementary logical forms (processual and thematic, respectively) of the analytic tools helped to provide empirical corroboration of the findings. A set of cognitive mechanisms was identified that describe the information-processing operations involved in creative user appropriation. Using assumptions from distributed cognition, it was demonstrated that these mechanisms can describe those operations at the individual and collective levels. An integrative model which shows how the mechanisms explain user creativity at the individual level was then developed. It is called the Information Cycle Model of creativity. This thesis makes several contributions to knowledge. It develops a theoretical framework for analyzing interactions between users and systems that is designed to represent the cycles of ideation and enactment through which creative appropriation moves are developed. It also presents a model of the cognitive mechanisms involved in the discovery of novel appropriation moves. The thesis also contributes to current debates within IS about representational metaphors for user interaction with IT.