Purpose. Ranganathan's Laws of Library Science and continued refinements to his initial laws place identification of patron's needs and connection of those needs to library services of primary importance in libraries (Ranganathan, 1931; Crawford & Gorman, 1995; Noruzi, 2004). Identifying and developing personas or user group descriptions helps to identify the unique nature of library patrons. Each persona helps librarians to identify or create services specific to the persona of library patrons. As each library persona is better understood, the library faculty and staff are able to prepare and plan for service delivery. Initially personas were developed for undergraduate students followed by the identification and development of personas for graduate students and faculty. This paper focuses on the identification and development of the undergraduate patron personas. Design, methodology or approach. The identification and development of undergraduate patron personas engaged communications students, as part of their coursework, to use a review of previous studies to develop theories of library patron personas. Each of the three groups within the communications class verified their initial persona theories using surveys, focus groups, interviews, observations and ethnographic methods. All personas from each group was further developed and refined into a final list and description of 10 library personas. A principal components analysis helped to provide interconnections between the personas and estimate the percent of patrons each persona comprised. Findings. The study identified 10 personas (user groups) who use a wide variety of library services. Descriptions of personas enabled library faculty and staff to identify personas accessing their services, to further develop and refine current services and to create new services to meet the needs of patrons. A principle components analysis further facilitated the understanding of interrelations between the personas based on persona use of library services. Personas that had common needs or use patterns were grouped together to further understanding of patrons use patterns and needs. While an attempt was made to determine the percent of total patrons each persona was, evidence was found that indicated the fluid nature of personas in regards to library services. That is, as the patron needs shifted, so did their persona. Patrons moved from one persona to another to meet their shifting needs as the academic semester proceeded. Research or practical limitations or implications. The identification and description of personas has several practical implications for librarians. First, when the personas enable librarians to reflect on the services they provide in terms of specific personas. This reflection enables the refinement and development of library services to meet patron needs. Second, understanding of the interconnection of persona needs enables librarians to market other services. For example, as a patron uses one service, librarians are able to point out related service...