Observed Learning Gains During an Inquiry-Based Molecular Visualization Intervention in Secondary Biology

This quantitative classroom study examined changes in students' cognitive scores following a four-hour inquiry-based biology intervention using authentic molecular visualization resources (iCn3D and Protein Data Bank structures). Participants were 83 Greek eleventh-grade students assessed using a one-group pre-test/post-test design. For each student, mean proportions of correct responses were calculated for Group 1 items, Group 2 items and all 18 cognitive items. Paired-samples t-tests showed higher post-test scores for Group 1 (Mpre = 0.32, Mpost = 0.83, Cohen's dz = 2.37), Group 2 (Mpre = 0.47, Mpost = 0.69, dz = 1.12), and all items (Mpre = 0.40, Mpost = 0.76, dz = 2.21; all p < 0.001). Girls had higher absolute composite scores at both time points, but pre-post gains did not differ significantly by gender (p = 0.523); therefore, the data do not support gender-specific instructional recommendations. Students also reported positive perceptions of the intervention and the visualization tool. These findings document short-term within-cohort score gains; because the study did not include a control group, they should not be interpreted as causal evidence of instructional effectiveness.