2026 ASEE Annual Conference & Exposition

In this full methodological paper, we reflectively examine the ambiguous process of determining theoretical saturation in constructivist grounded theory (CGT) studies. Despite CGT’s prominence in engineering education research (EER) for developing theories from qualitative data, such as engineering identity and motivation, prior literature frequently treats saturation as a vague endpoint, lacking explicit guideposts for operationalization. This opacity can undermine research quality and transparency. Drawing on critiques from qualitative methodology sources and our own experiences in two CGT studies, we explicate transparent guideposts to help novice researchers in assessing when data collection and analysis have yielded theoretically complete models.

We base our analysis of theoretical saturation on reflective logs from two different CGT projects. For the first study, we conducted semi-structured interviews with 15 practicing engineers from diverse disciplines, recruited through institutional networks tied to capstone courses. Following Charmaz’s constructivist grounded theory, we conducted initial coding concurrently with interviews, followed by focused coding and iterative category refinement through memo-writing to develop theoretically complete models. We assessed saturation throughout the process using memos that documented qualitative indicators, including redundancy in themes, the absence of new focused codes or novel ideas after the eighth interview, and theoretical depth across transcripts. In the paper, we illustrate how we did not use quantitative metrics; instead, we ensured that major themes appeared repetitively and provided nuance without introducing new categories. We addressed a key challenge—the variability in participants’ job responsibilities—by balancing contextual details with broader conceptual patterns.

In the second study, we conducted unstructured interviews with 20 engineering faculty to understand the nuanced and complex connections between faculty experiences of professional shame and their surrounding engineering climates. In line with best practices for conducting CGT, we completed initial coding and then synthesized those codes to craft focused codes. After applying our focused codes to each transcript, we completed in-depth memoing on each focused code, which allowed us to assess theoretical saturation by tracking similar patterns in the data and identifying when categories were well integrated and fully specified in relation to others. We illustrate in this paper how, by comparing memos, we were better equipped to determine whether new data refined the emerging theory or simply reaffirmed what had already been captured.

In the paper, we leverage our reflective findings to outline explicit guideposts for saturation, such as monitoring memo-documented redundancy after initial interviews, verifying theme repetition across diverse narratives, and confirming theoretical completeness during coding stages. These findings help advance CGT in EER by offering a practical, evaluative tool tailored to studies of engineering phenomena, where participant diversity demands flexible yet rigorous criteria. The implications include recommendations for EER researchers, such as integrating memo-based checkpoints into CGT workflows to enhance transparency and research quality. Our work promoted broader adoption of structured saturation processes, improving the validity of CGT applications in EER and related fields.