Recent research supports the benefit of students' construction of relevance through writing about the connection of content to their life. However, most such research defines relevance narrowly as utility value--perceived instrumentality of the content to the student's career goals. Furthermore, the scope of phenomenological and conceptual dimensions that characterizes students' perceptions of relevance remains largely unexplored in the literature. Rather, scholars have equated relevance with specific constructs such as utility, value or interest, which in turn has yielded a narrow conceptualization of relevance, usually constrained to a single construct, most commonly, utility. Whereas prior research certainly provides important insights into some of the features of relevance, it falls short of portraying the full scope of meanings that perceived relevance might take. To address this gap in the literature, this mixed-methods dissertation study explored the conceptual and phenomenological landscape of perceived relevance by employing a broad multidimensional conception of relevance to examine (a) the dimensional variability of students' relevance constructions; and (b) the individual characteristics and the motivational and identity processes underlying differences in their constructions of relevance. The context of this study was an Institute of Educational Science (IES)-funded semester-long multi-modal intervention project that aimed to promote learning, motivation and achievement in an undergraduate introductory biology course. One module within the intervention involved students' engagement in four relevance writing assignments, each focusing on a central biology concept in the course. The following dissertation employed data collected as part of this intervention project. This study involved coding and analyzing students' relevance writing about two biology concepts--evolution (n = 50) and organismic diversity (n = 38)--with the purpose of characterizing dimensions underlying undergraduate students' relevance constructions of central biology concepts and comparing these constructions across the two different biology concepts. Exploratory qualitative analysis procedures were used in the first phase of this investigation to develop an initial coding framework via intensive content analyses of students' relevance writing products on evolution. A second phase of qualitative content analyses of students' relevance writing about organismic diversity led to further development of the coding framework and comparative analyses of written products across the two concepts. Findings supported the dimensional variability of relevance constructions including the self-aspect connected to the content, the kind of connection made, and the type of perceived value, with some notable differences between the two biology concepts. Finally, the findings suggested that the meaningful connection engendered by the relevance construction experience originates primarily in the experience of understanding one's self within the relation--understanding the self in relation to the relevant content; and that understanding some content in relation to a component of one's identity may be secondary to the disclosure of the self. This dissertation explored the ways in which the relevance construction experience is a vital, dynamic process of identity formation. It is the findings from these intensive analyses that are reported in detail in this dissertation along with an in-depth discussion of the theoretical, methodological, and practical implications of this content-specific, multidimensional, identity-based conception of relevance. [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.]