From the thesis: "This thesis analyzes why Transportation Security Administration (TSA)--despite its remarkable success in its safety functions and human-technology interface--disregards best practices in curbing human error related to cognitive workload, fatigue, and motivation and trust, for which the organization has collected data since 2002. TSA has yet to record a serious human error incident to catalyze organizational change, but poor worker performance, as demonstrated in covert test results, confirms that minimizing human error in all facets of the complex system is crucial for sustaining TSA's future. Using the constant comparative method, this thesis explores literature on human factors (HF) and human error and analyzes the work environments of employees in the aviation security, aviation safety, and medical fields. Recognizing this gap between technological and procedural advancement and TSA's deficiencies in identifying the sources of human error, this thesis offers the following practical recommendations to facilitate a culture that reduces human error: initiate a pilot study, implement minor changes to the overall organizational culture within the screening environment, devise comprehensive HF policies and practices, and review existing data sets to reduce human error."