Impact of Inquiry-Based Learning on Undergraduate Biology Conceptual Reasoning

Thesis Abstract

This study investigates the impact of Inquiry-Based Learning (IBL) on undergraduate biology students’ conceptual reasoning, addressing the persistent gap between procedural laboratory experiences and the development of higher-order reasoning in biology education. The aim is to determine whether IBL enhances students’ ability to apply core biological concepts to novel problems, justify experimental designs, and construct coherent explanations grounded in evidence. Specific objectives include (1) comparing conceptual reasoning gains between IBL and traditional laboratory instruction, (2) examining the relationship between students’ epistemological beliefs and IBL outcomes, (3) exploring how different scaffolding levels within IBL influence reasoning complexity, and (4) identifying contextual factors that moderate the effectiveness of IBL in diverse biology courses. The study employs a quasi-experimental design within two intact undergraduate botany and physiology courses at a large public university, with a total enrollment of approximately 420 students across two consecutive semesters. A total of 320 students participate, with 160 in the IBL condition and 160 in the conventional instruction condition, matched on prior achievement, gender, and major. Data collection uses a mixed-methods approach (i) a validated Conceptual Reasoning in Biology Instrument (CRBI) administered as a pretest, posttest, and a delayed posttest at eight weeks, (ii) written argumentation tasks analyzed for coherence, evidence-based justification, and use of mechanistic reasoning via a coding scheme informed by the Rationality of Scientific Arguments framework, and (iii) semi-structured focus group interviews with a purposive sample of 40 students to illuminate perceived cognitive processes during inquiry activities. Instruments’ validity and reliability are supported by a panel of biology education researchers and a pilot study (Cronbach’s alpha for the CRBI = 0.89; inter-rater reliability ? = 0.82 for the argumentation coding). Data analysis follows a sequential explanatory design. Quantitative data are analyzed using analysis of covariance (ANCOVA) to compare posttest scores between groups while controlling for pretest performance, complemented by hierarchical linear modeling to account for nested data within laboratory sections. Regression analyses examine the predictive power of epistemic beliefs and perceived autonomy on conceptual reasoning gains. Qualitative data from focus groups are transcribed and subjected to thematic analysis to identify patterns in cognitive strategy deployment, with triangulation across data sources to strengthen inference validity. The theoretical framework integrates Constructivist theory and the Ausubel–Novak meaningful learning orientation with the Cognitive Apprenticeship model to explicate scaffolding and social negotiation in knowledge construction during inquiry activities. It is anticipated that the IBL condition will yield statistically significant improvements in conceptual reasoning (mean posttest gain, Cohen’s d ? 0.50–0.75) relative to traditional instruction, with larger effects among students exhibiting higher autonomy and more sophisticated epistemic beliefs. The study also expects that scaffolding intensity will moderate outcomes, where moderate scaffolding yields greater gains in argumentation quality and mechanism-based explanations than either minimal or excessive guidance. Findings will contribute to knowledge by empirically validating a scalable, theory-informed instructional approach that connects inquiry practices with core biological reasoning, addressing a critical need in undergraduate biology education to bridge laboratory experiences with transferable conceptual understanding. Practical implications include recommendations for curriculum design, instructor professional development, and assessment alignment that emphasize argumentation, evidence-based explanation, and mechanistic reasoning. The study concludes with implications for policy and practice, suggesting that integrating structured inquiry with targeted scaffolds can yield meaningful improvements in students’ conceptual reasoning and prepare undergraduates for sophisticated scientific problem-solving. Limitations include potential classroom variability in implementation fidelity and the generalizability restricted to similar institutional contexts. Suggestions for further research include replication across diverse disciplines within biology, longitudinal tracking of reasoning trajectory into upper-division courses, and exploration of technology-enabled inquiry environments to sustain gains.