Abstract

Augmented reality (AR) is increasingly used in STEM laboratories, but its pedagogical value depends on how digital guidance is embedded within structured physical learning activities rather than on technological novelty alone. This study examined an AR-supported hydropower laboratory activity designed around Kolb’s experiential learning cycle and rule-based instructional scaffolding informed by Vygotsky’s Zone of Proximal Development. A total of 202 participants completed a post-intervention questionnaire measuring learner digital readiness (LDR), perceived AR scaffolding quality (ARSQ), perceived AR experience design quality (AREDQ), and student engagement (SE). Structural equation modeling was used to examine the associations among these constructs. LDR was positively associated with ARSQ (β = 0.720) and AREDQ (β = 0.465), ARSQ was positively associated with AREDQ (β = 0.448), and AREDQ showed the strongest direct association with SE (β = 0.737). The model explained 54.3% of the variance in SE. These findings should be interpreted as perception-based cross-sectional associations rather than causal effects. Although convergent validity was supported, HTMT results indicated substantial overlap among some constructs, particularly ARSQ and AREDQ, highlighting the need for further measurement refinement. The study contributes a transparent design protocol for linking physical laboratory tasks, Kolb-aligned learning stages, rule-triggered AR support, and progressively reduced instructional guidance. Future research should validate the framework using broader measurement scales, objective performance indicators, control-group comparisons, and longitudinal learning outcomes.