From microstructural evidence to research engagement: an analytical transfer and engagement model for sustainable geotechnical education

Introduction Undergraduate geotechnical laboratories often develop procedural competence but provide fewer opportunities for students to interpret uncertain evidence, connect microstructure with engineering behavior, and evaluate sustainability-oriented decisions. Methods This classroom-based descriptive curriculum evaluation examined a research-integrated module embedded in a regular Fundamentals of Geotechnics course. The module combined conventional soil characterization, chitosan-based stabilization, scanning electron microscopy, ImageJ-assisted analysis, open-ended engineering explanation, and differentiated engagement pathways for 50 civil engineering students without increasing contact hours. Results Mean scores were 83.28 +/- 6.67 for theory, 82.20 +/- 6.28 for laboratory work, 79.10 +/- 7.28 for research-oriented tasks, and 78.28 +/- 7.42 for open-ended analysis. The structured-task mean was 82.74 and the interpretation-intensive mean was 78.69, yielding an Analytical Transfer Gap (ATG) of 4.05 points. Because paired component-level records were unavailable, ATG is presented as a provisional descriptive course-level statistic rather than a validated measure of individual learning transfer. Student responses were favorable, although the unvalidated three-option survey and possible social desirability effects limit interpretation. Discussion The Analytical Transfer and Engagement Model (ATEM) links this diagnostic pattern and the Integrated Learning Index with guided support, extended inquiry, and collaborative research participation. The findings suggest that sustainability-oriented microstructural inquiry may support analytical reasoning, digital evidence use, sustainability-oriented judgment, and research engagement. The study evaluates curriculum implementation rather than causal effectiveness.