School guidance support and growth in mathematics discourse feedback skills: a three-wave longitudinal mediation study

Introduction: Feedback improves learning when students can interpret evaluative information, justify reasoning, monitor progress against explicit criteria, diagnose errors, and implement targeted revisions in classroom dialogue. This study tested whether school guidance support fosters growth in mathematics discourse feedback skills through motivational and behavioral mechanisms. Methods: We used a three-wave longitudinal design with Chinese senior high school students. School guidance support was assessed at T1, major decision-making self-efficacy at T2, feedback literacy behavior at T3, and mathematics discourse feedback skills at all waves. Longitudinal measurement invariance was established for the outcome. Hypotheses were evaluated with structural equation modeling that controlled for prior levels of the outcome and demographic covariates. Missing data were handled with full-information maximum likelihood, and indirect effects were tested with bias-corrected bootstrapping. Results: T3 feedback literacy behavior. A sequential pathway from T1 guidance support to T2 self-efficacy to T3 feedback literacy behavior, and in turn to T3 mathematics discourse feedback skills, was also supported. The pattern is consistent with a time-ordered mechanism linking contextual supports, agentic beliefs, feedback-using behaviors, and discipline-specific skills. Discussion: Findings integrate social cognitive, feedback literacy, and self-regulated learning perspectives by specifying how school-level supports translate into domain-specific competencies. Practically, the results suggest a design principle for secondary schools: strengthen decision-making self-efficacy early, engineer routine opportunities to seek, interpret, and apply feedback, and then assess discourse-based reasoning and revision as proximal indicators of skill growth.