The purpose of this study was to investigate whether differences in thinking styles exist between senior level library administrators working in public and technical service areas in libraries with an institutional membership in the Association of Research Libraries (ARL). To facilitate this investigation, the Inquiry Mode Questionnaire (InQ) and a demographic data form were distributed in a nation-wide survey. The study achieved an 80.3% (106) return rate, with a total of 97 surveys used for data analysis. The literature review is organized in three segments: definitional dilemma, theoretical framework, and review of previous research. The definitional dilemma addressed issues concerning four similar, but not interchangeable, terms of cognitive styles, learning styles, personality styles, and thinking styles. Data analyses included five analyses of variance (ANOVAs) to determine relationships, differences, and interactions based upon the subject's administrative role (public or technical), gender (female or male), and thinking style preference (synthesist, idealist, pragmatist, analyst, or realist). The dependent variable associated with this study was thinking style preference (synthesist, idealist, pragmatist, analyst, and realist). The two independent variables associated with this study were administrative role (public or technical service) and gender (female or male). As part of the ANOVA process, the interaction between gender and administrative role was analyzed. Data analysis also included descriptive information analysis, a cross tabulation computation, and a dyad comparison. None of the 15 null hypotheses could be rejected based upon the ANOVA statistical computation using a.05 alpha level. However, the cross-tabulation and dyad analysis did reveal noteworthy findings, such as female library administrators were more likely to be idealist thinkers; male library administrators were more likely to be pragmatist and idealist thinkers; technical service administrators were more likely to be analyst, idealist, and pragmatist thinkers; and public service administrators were more likely to be idealist thinkers. Five findings were summarized in this study. They are: (a) the sample had a preference towards the flat thinking style; (b) a relationship between gender and thinking style exist; (c) a relationship between area of administrative responsibility and thinking style exist; (d) a difference in preferred thinking styles among administrative peers in the same institution was uncovered; and (e) the demographic analysis supported previous studies urging aggressive recruitment and diversity efforts for the library profession. Seven conclusions were highlighted in the study. They are: (a) the potential for developing the flat thinking style among the librarians participating in the study, (b) the influence of gender upon thinking style preference, (c) the influence of organizational differentiation upon thinking style preference, (d) the lack of previous research connecting thinking style research with librarianship, (e) the effects of team-based management implementation upon thinking style preference, (f) the influence of a non-diversified organization upon thinking style preference, and (g) an explanation for generalizations and stereotypes among library administrative peers. Recommendations for future study and enhancement of library management were included. Suggestions for improving library administration included incorporating thinking style research to help facilitate: (a) understanding among co-workers, (b) improving organizational communication, (c) providing opportunities for personal growth, and (d) providing opportunities for organizational growth.