The purpose of this study was to identify feelings and behaviors of fieldwork supervisors in public libraries using Lev Vygotsky's Zone of Proximal Development theory as a background for design, analysis, and discussion of results. This research sought to find out how fieldwork supervisors perform initial assessments of their fieldwork students, what activities and assignments are conducted during the experience, how the supervisors assess the students, and how they feel about their role in the process. The study began with an online survey (77 respondents), continued with 25 interviews, and concluded with a content analysis of 47 evaluation forms provided by library and information science education programs. Results of the survey and interviews were compared to the evaluation forms and the American Library Association's Core Competences of Librarianship. Results give a better understanding of the thoughts and actions of fieldwork supervisors in public libraries, and a new fieldwork evaluation form is proposed. [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://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]