Existing research suggests that dominant epistemic values in engineering might also shape diversity, equity, and inclusion issues in the discipline by working to marginalize the work and contributions of people of color and women. In this study, Trevion Henderson examined the role of dominant epistemologies in shaping first-year engineering design processes, including the ways that students evaluate, negotiate, and select ideas in team-based learning settings. Using a convergent parallel mixed-methods design, the study combines a qualitative critical ethnographic strand with a quantitative network analysis strand to examine how students in team-based learning settings discussed, negotiated, and ultimately chose or discarded ideas during a semester-long design project. To date, findings indicate that (a) students understood and responded to dominant epistemologies differently, (b) dominant epistemologies shaped interactions during design discussions, and (c) the mechanisms students used to wield, or subvert, dominant epistemologies ultimately shaped the ideas teams pursued and discarded. These results suggest understanding the epistemic culture of the discipline is a key area for teaching and learning in engineering, particularly for those seeking to address diversity, equity, and inclusion issues.