Fig. 5

Concepts present in student explanations of the evolution of antibiotic resistance in a microbial population. Post-instruction, students in spring 2014 in both the LB145 classroom that used Avida-ED (n = 100) and the LB145 classroom that did not use Avida-ED (n = 87) were asked, “Explain how a microbial population evolves resistance to the effects of an antibiotic”. Responses were assessed for the presence of concepts identified using content analysis. Significance of differences within categories was assessed using Chi squared tests. **p < 0.01; *p < 0.05. Effect sizes reported as odds-ratios per Maher et al. (2013)