Undergraduate research experiences (UREs) in science and engineering offer a number of positive outcomes to the students who are able to participate, including increased retention, clarified career goals, and development of problem‐solving skills. There have been a number of calls for research that investigates the experiences, identity, and cognitive develop of students who participate in UREs. In addition, recent work in other areas suggests that undergraduate students' perceptions often differ from those of faculty, graduate students, and staff, suggesting the need for research that considers the students' perspectives within these experiences. As such, in this constructivist grounded theory study, we sought to develop a contextualized model relating researcher identity and epistemic thinking for undergraduate engineering students engaged in research experiences. Data were collected from interviews with 20 undergraduate engineering students with research experience at six institutions. Coded interview transcripts were used to create structured memos that included a participant description, summary of salient concepts from theoretical frameworks and/or themes, and connections to other participants. These structured memos served as the data set used to develop the grounded theory model. This work establishes that (1) students' initial dispositions and beliefs about research influence their perceptions of researchers and themselves as researchers (researcher identity), (2) researcher identity can dissolve or solidify through UREs, (3) researcher identity affects and is affected by students' reflection on research practices, and (4) social interactions and context shape knowledge of research and researchers, researcher identity, and interest in research. Our work expands existing identity and epistemic thinking theories by investigating how students establish a researcher identity, conducting a context specific study of epistemic thinking, and exploring the relationships between these two constructs.
