Enhancing Middle School Students’ Conceptual Understanding in Science through the Anticipation Guide Strategy

Persistent deficits in students’ conceptual understanding of science, particularly within Indonesian secondary education, underscore the urgent need for evidence-based instructional interventions that transcend conventional, transmission-oriented pedagogical practice. This study examined whether the implementation of the Anticipation Guide (AG) strategy produces a significantly greater improvement in seventh-grade students’ conceptual understanding of science compared to conventional lecture-based instruction. A quasi-experimental nonequivalent pretest–posttest control group design was adopted. Fifty-two seventh-grade students from SMP Negeri 1 Geyer were assigned to an experimental class (n = 26; AG-based instruction) and a control class (n = 26; conventional lecture-based instruction). Both classes studied the topic of Earth and the Solar System over four 80-minute sessions. Conceptual understanding was assessed using a validated 25-item multiple-choice instrument with a KR-20 reliability coefficient of 0.78. The Shapiro–Wilk test confirmed non-normal score distributions; accordingly, the Wilcoxon signed-rank test was employed for inferential analysis. Normalized Gain (N-Gain) scores were computed to quantify the practical magnitude of pre-to-post improvement. The experimental class demonstrated a statistically significant pre-to-post improvement (Z = −4.489, p < 0.001; N-Gain = 0.436, Moderate category) alongside a pronounced reduction in score variance (34.46 → 10.15). No significant improvement was observed in the control class (Z = −1.003, p = 0.317; N-Gain = 0.012, Low category). The AG strategy, by activating prior knowledge, scaffolding evidence-based evaluation of scientific texts, and reinforcing conceptual consolidation through post-reading reflection, constitutes a significantly more effective instructional approach than conventional direct instruction for promoting conceptual understanding in secondary science education. The study contributes empirical evidence to the limited body of research on reading-based epistemic strategies in under-resourced secondary school contexts.