A Task-Driven Activation Framework for Critical Thinking in Project-Based Learning: A Narrative Review of Subskill-Level Evidence

XUE HU^*

• University of Science Malaysia (USM), Penang, Malaysia

Project-based learning (PjBL) has been widely promoted as an instructional approach capable of developing critical thinking (CT), yet empirical findings remain contradictory. Some studies report substantial effects (d = 1.04; η² = 0.70), while others yield null results. This narrative review synthesizes empirical research on how PjBL influences CT development, with attention to subskill-level evidence and the conditions under which interventions succeed or fail. Analysis reveals that outcome variability stems primarily from differences in implementation quality, specifically task authenticity, scaffolding structures, and intervention duration, rather than inherent limitations of the approach. More critically, studies overwhelmingly report composite CT scores, obscuring which specific cognitive abilities are activated during project work. To address this gap, the review proposes a task-driven activation framework integrating Facione's skill-based taxonomy with Halpern's process-oriented model. The framework posits that CT subskills are triggered sequentially across PjBL phases rather than developing uniformly. Interpretation and analysis have low activation thresholds, while inference and evaluation require authentic decision-making contexts. Self-regulation emerges through iterative feedback cycles, and explanation is activated when students defend reasoning to authentic audiences. This sequential perspective offers a process-level explanation for contradictory findings and generates testable hypotheses about task-subskill alignment. The review advances current understanding of how PjBL engages higher-order cognition. Implications for instructional design and future research priorities are discussed.