The study explores the nature and extent of educational intervention in public universities in the form of the non-academic inputs of student affairs or services. A multi-site case study of seven Philippine state universities was conducted using grounded theory as a vehicle for theory-building. Each site represented different sizes in student population, academic focus, geographic locations and types of location (rural and urban). A total of 107 interviewees including university officials, alumni, students, faculty and student affairs practitioners served as resource persons, with their responses validated against university documents and site observations. The study puts forward a substantive theory on student development. It takes into account the embedded nature of the process of student transformation - itself a product of experience and choice. Student experience is defined by internal and external environmental factors, whereas choice is generated through a decision-making sequence composed of motivation and personal goal formulation. The study finds theoretical grounding in the various fields of psychology, social science, and educational management.