Instructor clarity is a central component of instructional communication and has been consistently associated with positive academic outcomes; however, less evidence exists regarding the mechanisms through which it influences student interest in higher education contexts. From a sustainability perspective, understanding these mechanisms is essential for promoting inclusive, equitable, and high-quality learning environments in line with global educational goals. This study fills a gap in the literature by examining, through multivariate models, the relationship between instructor clarity and student interest as mediated by academic satisfaction and state motivation, within the framework of the Rhetorical/Relational Goals Theory in the Spanish higher education context. A quantitative, cross-sectional, ex post facto research design was employed using a survey method. A non-probabilistic convenience sampling approach was used. A total of 258 undergraduate students from the University of Extremadura enrolled in the Bachelor’s Degree in Early Childhood Education and the Bachelor’s Degree in Primary Education participated in the study. Data were analyzed using Partial Least Squares Structural Equation Modeling (PLS-SEM), including an assessment of the model’s predictive capability. The results indicated that instructor clarity was positively associated with academic satisfaction, state motivation, and student interest, with the first two variables acting as complementary mediators in these relationships. Among the predictors, state motivation emerged as the strongest determinant of student interest, whereas the direct effect of instructor clarity was comparatively weaker, highlighting the relevance of indirect pathways. The model demonstrated high predictive power and strong predictive validity with respect to student interest. Overall, the findings indicate that instructor clarity influences student interest primarily through its indirect effects on academic satisfaction and state motivation, emphasizing the importance of fostering motivational processes as key mechanisms linking teaching practices with students’ learning outcomes in higher education. Finally, it should be noted that the findings are directly aligned with Sustainable Development Goal (SDG) 4, contributing to Target 4.3 by enhancing the effectiveness and equity of teaching in higher education, as well as supporting the development of sustainable learning environments that foster long-term student engagement and academic persistence.
Froment et al. (Wed,) studied this question.