  Improving the physics enterprise to broaden participation in physics is one
of the main goals of the physics education research community. Many classically
trained physics faculty transition during their faculty career into engaging in
research investigating the teaching and learning of their discipline. There is
scarce research on the support and needs of these faculty as they engage in
their first projects in this new research field for them. We investigate agency
growth of two emerging physics education researchers and one emerging
mathematics education researcher as they participate in a professional
development program. We ground our case study analysis of interview data in a
theoretical framework on agency. We identify the elements of the professional
development program that were transformative in our case study participants'
trajectory in education research. Receiving get-started information, building
mechanisms to sustain research projects and engaging with a supportive
community help participants transform general interests to specific questions,
articulate concrete next-steps and increase their sense of self-efficacy.
During this professional development program all three case study participants
gain agency in this new area of research for them. These identified program
elements that affect agency growth can inform professional development
opportunities for faculty transitioning into discipline-based education
research, which expands our understanding of how to build capacity in the
field.
