This study examined the effects of using Appreciative Inquiry in accreditation and related institutional effectiveness activities within higher education. Using an explanatory participant-selection mixed methods approach, qualitative data from a series of interviews were used to explain the experiences of individuals identified from quantitative survey results. Appreciative Inquiry is a theoretical framework for action research, organizational development, and evaluation that emphasizes the positive aspects of human systems. In recent years, Appreciative Inquiry has been applied specifically to improvement activities associated with regional accreditation, such as the Vital Focus self-assessment that precedes the transition to the Higher Learning Commission's AQIP process. Few studies have attempted to identify common attitudes or themes across multiple institutions using Appreciative inquiry, and no prior studies have addressed the specific impact of Appreciative Inquiry-based accreditation activities. In the initial quantitative phase of the study, ANOVA procedures failed to detect a significant difference in perceptions of either institutional or individual change among three levels of participation. Multiple regression analysis indicated that on-going communication and allocation of resources around the inquiry results are two characteristics most strongly correlated with perceptions of positive institutional change. These two characteristics, along with having a positive topic, continuation of project teams, and training on theory underlying the process, also correlated strongly with perception of positive individual change. The mixed methods results explained these statistical findings in greater breadth and depth by linking them to the results of the qualitative interview phase of the study. Participants described structural and climate changes at their institutions as well as changes in themselves regardless of their level of participation. The stories told by the interview participants reinforced the characteristics of Appreciative Inquiry that correlated with perceptions of change in the statistical analyses and showed the different forms that these characteristics might take at different institutions. Overall, the findings suggest that institutional effectiveness activities based on highly inclusive, open conversations on positive topics, which are supported in all phases by administration, have great potential for changing institutions and individuals in a positive way. Appreciative Inquiry adds value to the accreditation process in higher education institutions. [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.]