Axial coding is a set of procedures in which data are reassembled in new ways after open coding, by making connections between categories. This is performed by utilizing a coding paradigm involving conditions, context, action/interactional strategies, and consequences [39] (p. 96). Based on this paradigm model, as shown in Table 2, this study gathered the scattered categories generated by open coding, reorganized and conceptualized data around the central phenomenon, and established initial associations between categories and their properties.

Selective coding is the process of identifying the core category, systematically relating it to other categories, validating those relationships, and filling in categories that need further refinement and development [39] (p. 116). Selective coding involves clarifying the core category that integrates other categories through explicating the story line to generate a grounded theory. In this study, after conceptualizing the research topic through the story line, the core category "Doctoral students' understanding of academic identity" was determined based on theoretical sensitivity. "Sense of academic meaning" and "sense of academic efficacy" were identified as two properties of the core category. As illustrated in Table 3, guided by these properties, the core category was divided into four patterns: Adeptness, Academic Pursuit, Alienation and Powerlessness, and Struggling for Meaning.

These four patterns represent diverse types of student understanding the academic identity. "Adeptness" characterizes doctoral students who have a strong sense of academic meaning and efficacy, generally positioning themselves within or near the academic com- munity. "Academic Pursuit" applies to doctoral students with strong academic meaning

but low efficacy; they usually position themselves on the periphery of the academic com- munity. "Alienation and Powerlessness" refers to individuals with a low sense of both academic meaning and efficacy, who often feel alienated and incompetent. "Struggling for Meaning" describes doctoral students who have a weak sense of meaning but a strong sense of efficacy, frequently encountering conflicts and internal struggles about meaning.

Finally, after validating these relationships against the data, it appeared that this study achieved theoretical saturation. Therefore, the grounded theory generated in this study is that the extent to which doctoral students perceive a sense of academic meaning and efficacy influences their understanding of academic identity.

The primary researchers for this study were former doctoral students, with divergent perspectives on academic culture, ranging from viewing it as a noble pursuit to merely a means of livelihood. Due to the diversity of researchers' personal positions, this study performed the data analysis with reflexivity and collaboration. Recognizing the varied backgrounds and viewpoints of the researchers, the analysis was conducted with a critical eye, acknowledging individual biases. Meanwhile, researchers strived to adopt the perspectives of the participants during data analysis, extrapolating their view and methods of constructing meanings from their words and actions, thereby ensuring that the researcher's interpretation was as close to reality as possible. To ensure the trustworthiness of the findings, peer debriefing and member checking sessions were undertaken, with preliminary interpretations presented to academic supervisors and fellow doctoral students. This collaborative process facilitated rigorous scrutiny of the interpretations and enriched the analysis, ultimately enhancing the credibility of this qualitative research.

In this study, to thoroughly present the grounded theory generated by the data, we first describe the psychological process by which doctoral students understand their academic identity. We then analyze the various patterns of this understanding and discuss the reasons for differences in Chinese doctoral students’ understanding of academic identity.