Developing critical thinking through scaffolded peer feedback: an action research on heuristic design.

Introduction: Although peer assessment has been shown to promote critical thinking, its effectiveness depends heavily on structured guidance. This study aimed to design and validate a heuristic scaffolding framework embedded throughout the entire peer assessment process. Methods: Adopting an action research approach, the study conducted two iterative rounds of teaching practice. Textual data generated from peer assessments in both rounds were collected and analyzed using epistemic network analysis to quantitatively examine the co-occurrence relationships and structural connections among core elements of critical thinking, thereby evaluating the intervention effect of the scaffolding on students' critical thinking. Results: The findings indicate that the heuristic scaffolding effectively activated various elements of learners' critical thinking and facilitated the development of an interconnected cognitive network. While the initial scaffolding prompted the application of macro-level skills, a tendency toward "emphasizing evaluation over interpretation and reasoning" was observed. The optimized scaffolding, refined after the first round of intervention, significantly strengthened the cognitive chain from "evaluation to reasoning to self-regulation" and promoted the advancement of critical thinking to higher levels. Discussion: This study provides educators with a replicable scaffolding tool and a data-driven pathway for instructional improvement to design peer assessment activities that foster higher-order thinking.