This chapter explores cognitive problem-solving style and its impact on user resistance, based on the premise that the greater the cognitive difference (cognitive gap) between users and developers, the greater the user resistance is likely to be. Mullany (1989, 2003) conducted an empirical study demonstrating this. This study contradicts the findings of Huber (1983) and supports Carey (1991) in her conclusion that cognitive style theory, as applied to IS, should not be abandoned. Mullany’s findings, in fact, are the opposite. Kirton (1999, 2004) supported Mullany’s results. In particular, Mullany made use of Kirton’s (2004) adaption–innovation theory. The emergent instrument, called the Kirton adaption–innovation inventory (KAI; Kirton, 1999, 2004), was used by Mullany as his measure of cognitive style.