Integrating statistics with a microbiology laboratory activity

Statistics is an important tool for microbiologists but is virtually absent from undergraduate laboratory activities. The variables in a stringent protocol, the antibiotic disk diffusion assay described by the National Committee for Clinical Laboratory Standards, were examined by the authors as a means for introducing hypothesis testing and the application of elementary statistical tools. After several experiments, a lab activity was developed where students examine the effect of cell concentration on antibiotic activity and analyze data with the t test. They also collect data independently from the same samples and compare their measurements using analysis of variance (ANOVA). The outcome of the activity, including an assessment tool, indicated that students learned the appropriate use of the t test and ANOVA, gained an appreciation for standardized protocols, and enjoyed the experience.