Scaffolded Inquiry-Based Learning Versus Direct Instruction in Secondary STEM Classrooms: A Criterion-Referenced Comparative Analysis of Epistemic Cognition, Transfer Efficacy, and Metacognitive Calibration

Abstract

The pedagogical debate between scaffolded inquiry-based learning (SIBL) and direct instruction (DI) remains unresolved in secondary STEM education, particularly regarding long-term knowledge transfer and metacognitive development. This study employs a quasi-experimental, criterion-referenced design across six secondary institutions (n = 847 students, grades 9–11) to evaluate differential outcomes across three dimensions: epistemic cognition, near- and far-transfer efficacy, and metacognitive calibration accuracy. Standardized assessments, think-aloud protocols, and Gamma calibration coefficients were applied over two academic semesters. Results indicate that SIBL yields statistically significant advantages in far-transfer tasks (d = 0.61) and metacognitive calibration (d = 0.48), whereas DI demonstrates superior efficiency for procedural fluency acquisition. Moderation analyses reveal that prior knowledge level critically mediates instructional effectiveness, with novice learners benefiting disproportionately from DI scaffolding. These findings provide actionable frameworks for differentiated instructional design in heterogeneous STEM cohorts.