Thesis advisor: Larry H. Ludlow / In the field of teacher education, it is well documented that the most influential part is the clinical component, often referred to as student teaching or the practicum experience (Cochran-Smith, 1991; Darling-Hammond, 2014; Evertson, 1990). During the practicum, there exists a triad of three individuals: a university supervisor, a K-12 classroom teacher (often referred to as the cooperating teacher), and the teacher candidate. While much research has been conducted on teacher candidates and the cooperating teacher role, there has been a lack of research on the role of the university supervisor. The lack of measurement instruments to assess the quality of the university supervisor puts teacher education programs at a disadvantage, both from a programmatic improvement standpoint, as well as meeting accreditation requirements. This dissertation provides an answer to this issue, creating a new instrument that assesses the quality of the university supervisor, from the perspective of teacher candidates. This instrument is constructed under the Rasch-Guttman Scenario (RGS) framework, as most clearly defined by Ludlow, Baez-Cruz, et al. (2020). The RGS framework derives its influence from the works of George Rasch (1960/80) as well as Louis Guttman’s facet theory (Guttman 1954; Guttman 1957). The result is a new scale, entitled the University Supervisor Quality (USQ) scale, consisting of nine scenario items. All nine items include four facets that comprise the construct of university supervisor quality: resourcefulness, constructive feedback, mentorship, and collaboration. The results of this dissertation suggest that the utilization of the RGS framework is successful for developing a scale about university supervisor quality. In addition, the use of cognitive interviews provide valuable insight into the development of scales using the RGS framework. This scale has the potential for use in teacher education programs for evaluating the quality of their supervisors, and to utilize as evidence for accreditation purposes. / Thesis (PhD) — Boston College, 2022. / Submitted to: Boston College. Lynch School of Education. / Discipline: Educational Research, Measurement and Evaluation.