Recent literature suggests a problematic connection between theory and practice in higher education scholarship generally and the study of student learning and development specifically (e.g. Bensimon, 2007; Kezar, 2000; Love, 2012). Much of this disconnect stems from a lack of differentiation between various types of theory used in student affairs practice--critical among them: formal, informal, and implicit theories. Formal theory is produced by scholars and, to the maximum extent possible, conforms to standard social science assumptions about knowledge production, generalizability, and predictiveness (Parker, 1977). Since formal theory will not always apply perfectly to practice, student affairs practitioners may choose not to adapt it for their own uses as they create a theory-in-use--essentially a set of values, beliefs, and assumption that guide their practice (Argyris & Schon, 1974). Though there is some disagreement in the literature as to whether the use of formal theory is necessary (Evans & Guido, 2012; Love, 2012), most hold that the goal of higher education research is to influence practice through the production of relevant theory (Bensimon, 2007; Kezar, 2000). As a result, it is possible to distinguish between two different types of theory-in-use: implicit theory and informal theory. Implicit theories are a body of loosely considered values, beliefs, and assumptions that are not connected in any systematic way to relevant formal theories (Bensimon, 2007). In contrast, informal theories are based on formal theory but also include the understanding of context and relevant professional experience of student affairs practitioners (Parker, 1977). While determining the precise role of each of these types of theory is critical to theory-to-practice conversions (Reason & Kimball, forthcoming), no empirical work has yet examined the role that each plays in student affairs practitioners' conceptualizations of student learning and development. As such, this dissertation uses the extended case method (Burawoy, 1991; 1998; 2009) to examine the thinking of six academic advisors and three residence life professionals at a large public research university to address three linked research questions: 1) How do practitioners understand student experience? 2) What is the role of theory in that understanding? 3) What is the connection between theory and practice? Major findings reveal that the way that student affairs professionals think about learning and development are the unique products of the contexts in which they work. Effectively, these practitioners employ "guiding concepts" synthesized from formal theories as well as their own experiences in order to construct a flexible theory-in-use capable of useful application in a wide variety of situations within the environment in which they work. Additional findings suggest that learning and development, despite recent attempts to synthesize them (Reason & Renn, 2008), remain independent-yet-related concepts in the minds of the students affairs professionals who participated in this study. Important findings related to student affairs work also include an acknowledgment of the critical roles of technostructure--the systems, processes, and tools that enable a professional role to be constructed in a particular way--and the larger social context play in practice. Finally, in order both to honor and benefit from the knowledge of student affairs professionals, this dissertation closes by proposing a model of theory-to-practice-to-theory based on the extended case method and designed to allow for a tighter coupling between formal and informal theory. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]