Instructor support for postgraduate study intention in higher education: a moderated serial mediation model across GPA levels

This study examined the relationships among perceived instructor support, academic self-efficacy, academic engagement, and postgraduate study intention among undergraduate students using a moderated serial mediation framework. Specifically, it investigated whether these relationships and mediation pathways differed across students with low, medium, and high levels of academic achievement (GPA). A total of 751 undergraduate students from various universities in Türkiye participated in the study. Data were analysed within a general linear modelling (GLM)-based mediation framework using Jamovi software. The results indicated that perceived instructor support did not have a significant direct effect on postgraduate study intention in the overall model. Although a significant direct effect emerged among students in the low GPA group, this effect did not significantly differ from those observed in the medium and high GPA groups. Perceived instructor support exerted significant indirect effects through academic self-efficacy and academic engagement independently. Moreover, the indirect effect through academic engagement and the sequential pathway from academic self-efficacy to academic engagement were only significant among students in the medium and high GPA groups. In contrast, both indirect effects were non-significant among students in the low GPA group. Furthermore, GPA significantly moderated the relationship between academic engagement and postgraduate study intention, such that the positive association between academic engagement and postgraduate study intention was stronger among students in the medium and high GPA groups than among those in the low GPA group.