While program-level assessment has become common in higher education, questions remain about the impacts of assessment on teaching and learning in academic programs. Despite the considerable assessment activity happening in higher education, assessment scholars still have difficulty finding evidence of programs "closing the loop," that is using assessment to make meaningful improvements to teaching and learning (Banta & Blaich, 2010). Assessment scholars have called for more in-depth research on program-level assessment, noting a need for more research into how individual programs are engaging in assessment and what kinds of impacts assessment is having at the program level (Ewell, Paulson, & Kinzie, 2011). Using a qualitative case study approach, this study investigated the processes and impacts of assessment practice in an applied linguistics program in higher education. Data was collected over a two-year period, and data collection methods included participant observation, interviews, and document analysis. Lattuca, Terenzini, and Volkwein's (2006) Engineering Change model was used as an initial framework for data analysis and adapted over the course of the study. The findings revealed that the program experienced changes to faculty culture, administrative policies and practices, curriculum and instruction, and student experiences. However, specific changes within those categories often differed from those outlined in Lattuca et al.'s model. The study reveals the complexity of the assessment process and indicates that rather than follow a simple, unidirectional inquiry loop like the one presented in the assessment cycle, programs may need to engage in a number of challenging intermediate steps and detours as they work to use assessment to improve teaching and learning. The study also shows that with some modifications the Engineering Change model can be applied to research on assessment in programs without professional accreditation, such as an applied linguistics program, and used as a framework for research methods such as qualitative case studies. [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.]