Assessment of a virtual laboratory for teaching genetic drift
In this presentation we discuss the use of the Genetic Drift Inventory (GeDI), a concept inventory developed as part of a NESCent working group to create new concept inventories in evolution, for assessment of the effectiveness of an interactive computer-based laboratory on genetic drift at the undergraduate level. This virtual laboratory, developed independently from the GeDI, uses a conservation biology scenario with black-footed ferrets to teach key concepts in genetic drift, including sampling error, population size influences on the magnitude of drift, and the role of drift in the loss of heterozygosity in populations. Students alter parameters in dynamic models, test hypotheses, and design and assess a conservation plan for a virtual ferret population. We administered the GeDI to students pre and post-instruction in experimental (virtual lab) and control (conventional instruction) courses and compared overall gains on the GeDI, gains in key concepts, and reductions in the prevalence of alternative conceptions across treatment groups. Based on previous work with virtual labs for teaching complex evolutionary topics, we predicted that the virtual lab would lead to learning gains in genetic drift, and that those gains would be greater than those associated with conventional teaching methods. In addition, we sought to determine if those gains on the GeDI were due to improvements in understanding of key concepts, reductions in the prevalence of alternative conceptions, or improvements in both areas.
Preliminary data support the effectiveness of this virtual laboratory as an instructional tool for genetic drift at the undergraduate level. Virtual lab students showed significantly greater gains in overall scores when compared to control students. Use of the virtual lab led to an approximately 20% increase in overall score on the GeDI. Furthermore, these gains were reflected both in understanding of key concepts and in reductions in the prevalence of alternative conceptions. Encouragingly, virtual lab students improved even on alternative conceptions that were not explicitly addressed in the lab. It appears that an interactive computer-based simulation approach can be an effective means through which to support undergraduate student conceptual understanding of genetic drift.