The following dissertation is comprised of three manuscripts presenting a theory-to-practice design for studying the nature of knowledge change. Knowledge change—as defined for this dissertation—is an exploration of the quantitative and qualitative change in how knowledge is used over a period of time. Knowledge change is derived from the broader scholarship on conceptual change; that is, how people develop, organize, and then re-organize knowledge (Vosniadou, 2013). Conceptual change has been widely used to describe the cognitive process behind how a novice acquires and organizes knowledge in order to become an expert (Carey, 1985), particularly in the hard sciences (e.g. Science, Technology, Engineering, and Mathematics, or 'STEM' subjects) (Vosniadou, 2008, 2013). However, more recent research has been dedicated to establishing the need to explore conceptual change in the social sciences (Murphy and Alexander, 2008). The present research was designed to explore knowledge change as one specific component of the conceptual change process. The research is presented in three manuscripts. The first manuscript details how the researcher blended conceptual change learning with the disciplinary domain of the present study, leadership studies. The second manuscript chronicles the design of a continuous case study, the primary tool for data collection used in the present study, as well as the methodology used. The third and final manuscript offers an overview of the first study undertaken using the collected data; that is, an exploration of the nature of knowledge change within an undergraduate peer leadership course. / Ph. D.