- Providing transformational learning opportunities for undergraduate students demands changes to teaching practices. In large-enrollment introductory courses, graduate teaching assistants (GTAs) play an important role in facilitating student learning in small group environments. However GTAs are not provided the pedagogical development necessary to support them to be effective in their teaching practices. In order to provide GTAs with pedagogical development opportunities, we need an in-depth understanding of GTAs’ current teaching practice and how they are making pedagogical decisions, which is based upon their epistemological perspective. As it currently stands, there is limited research on GTA practice and epistemology in engineering, particularly in environments that expect them to implement complex, interactive learning pedagogies such as Studios in engineering (Koretsky, 2015). This dissertation contributes to the current literature around teaching practices and epistemology by focusing on GTAs’ epistemology and practice in engineering since they play a significant role in undergraduate students’ experience. This dissertation provides an in–depth case study of two engineering GTAs within a second term junior level thermodynamics Studio. It also investigates the creation, implementation, and reception of a series of pedagogical development seminars within a first year graduate student professional development seminar.Engineering educators implement active learning strategies as a way to engage students and improve their learning gains (Prince, 2004). However, these teaching practices are complex and require time, preparation, and skill to be able to implement them effectively. Windschitl and Barton (2016) provide ambitious teaching as a framework for looking at teaching practices. The authors identify two assumptions that bind cases of successful teaching practice. The first is that the quality of teaching is assessed by the engagement of all learners, which aligns with the goals of an active learning environment. The second is that sustainable improvements in teaching require a “repertoire of practices” that are refined over time. This repertoire of practices should be a part of a larger system of instruction that supports student learning. At a large research university, Studios are part of a program-level course redesign aimed at increasing the frequency of interactive learning in the classroom. Teaching practices that are important to Studio pedagogy are attending to group dynamics and eliciting student thinking through productive dialogue (Chi, 2009; Fonseca & Chi, 2011; Windschitl & Barton, 2016) and providing effective feedback (Gilbuena et al., 2015). Chapter 2 details the observed practices of two GTAs, Dean and Jeff (pseudonyms), in a junior level thermodynamics Studio course within two structurally different Studios: Studio 1 was conceptually oriented and lab based, whereas Studio 2 was procedurally oriented and required students to engage with mathematical concepts. The nature of and the frequency of the teaching practices of attending to group dynamics, eliciting student thinking, and providing effective feedback are investigated.Traditionally epistemology has been studied from a unitary perspective (Perry, 1970; Magolda, 1992; Belenky et al., 1986; King & Kitchener, 1994; Kuhn, 1991; Hofer & Pintrich, 1997). Hammer and Elby (2002) provide an alternative framework that takes context into account by identifying resources (e.g. knowledge as fabricated, knowledge as transmitted) and frames, which are stabilized structures of resources across multiple contexts. Methodologically when investigating epistemology and practice, researchers focus on an “enacted” and “professed” epistemology (Louca et al., 2004; Speer, 2005). Speer (2005) makes an argument that solely focusing on enacted and professed epistemology does not capture the nuances of the decisions being made within the classroom. She suggests using stimulated recall interviews (SRIs) to better understand the connection between epistemology and practice and to contextualize in-the-moment decisions instructors make. Chapter 3 builds on the work in Chapter 2 by investigating the enacted, professed, and reflected epistemological resources and frames (Hammer & Elby, 2002) of Dean and Jeff using SRIs. Dean and Jeff’s resources and frames are addressed within the practices of attending to group dynamics, eliciting student thinking, and providing effective feedback. Chapter 4 discusses the creation, implementation, and reception of a series of pedagogical workshops situated within a professional development seminar that all first year graduate students in an engineering school are required to take. These pedagogical workshops were created and implemented in an effort to “integrate researcher knowledge, practitioner experience, and new institutional structure for pedagogical experimentation” (Windschitl & Barton, 2016, p.1100) as part of the program level course redesign that includes Studios. The goals, seminar topics, main resources, and activities for the pedagogical development seminars are discussed. A survey was administered to graduate students to assess the contribution of the pedagogical seminars to the seminar goals and the effectiveness of seminar activities to the graduate students’ learning. The needs assessment model (Borich, 1980) was used to evaluate the effectiveness of the seminar in helping graduate students to develop pedagogical thinking.