Medical and veterinary students' structural knowledge of pulmonary physiology concepts

Purpose. The goal of this study was to assess quantitatively medical and veterinary students' knowledge structures of 12 pulmonary physiology concepts before and after receiving a focused instructional block. The 'goodness of fit' and internal consistency reliability of the students' knowledge structures were evaluated. Indexes of the students' structural knowledge were correlated with customary measures of student learning of the same concepts. Method. Knowledge structures were assessed using a questionnaire that requested similarity judgments about all possible pairs of the concepts: n(n - 1)/2 = 66 pairs. The similarity judgment data were analyzed using the individual differences (INDSCAL) model of multidimensional scaling (MDS). Dimension weights for individual students were then correlated with their final examination scores. Results. A four-dimensional MDS solution provided the best structural fit to the pairwise concept-similarity data. Dimension 1 ranges from control of breathing to lung gas exchange. Dimension 2 ranges from control of breathing to respiratory mechanics. Dimension 3 separates perfusion from diffusion. Dimension 4 addresses ventilatory control. Hierarchical concept clusters are located within this framework. However, indexes of structural learning did not correlate with other measures of knowledge about the same concepts. Conclusion. The study outcomes, in contrast to research in other fields, suggest that structural knowledge in this domain differs from knowledge assessed by standard examinations. Further research involving other basic science or clinical concept sets is needed to verify or refute this finding.