Impact of project-based learning on inorganic chemistry laboratory practices in agricultural higher education

Abstract

Introduction: Traditional laboratory teaching in inorganic chemistry at the university level usually prioritizes procedural compliance over critical reflection, limiting the active participation of students and weakening the integration of theory with professional practice. Objective: This study evaluated the association between a Project-Based Learning (PBL) intervention and changes in students' perception of laboratory practices within the agricultural engineering program of the State Polytechnic University of Carchi. Methodology: A quasi-experimental pre-test - post-test design was implemented with a quantitative approach. Fifty-one students participated in the diagnostic phase and 35 completed the pedagogical intervention organized in collaborative teams. Results: Data were collected through structured Likert-scale surveys, complemented by diagnostic observation and documentary analysis. Responses were dichotomized and analyzed using Fisher's exact test with Holm adjustment for multiple comparisons. Post-intervention outcomes showed consistent increases in favorable responses across all indicators assessed. Greater advances were observed in self-perceived experimental competencies related to acid-base balance and critical interpretation (+32.60 percentage points; RR = 1.55), active participation and theory-practice integration (+31.54 pp; RR = 1.50), and the integration of teamwork (+29.58 pp; RR = 1.46). Five of the six indicators showed statistically significant differences (p < 0.05). Conclusions: although overall satisfaction increased, statistical significance was not maintained after adjustment. These findings suggest that PBL-based contextualized teaching in the laboratory is associated with improvements in perceived involvement and experimental competencies in applied science programs. General Area of Study: Education. Specific area of study: Project-Based Learning. Type of article: original.