These 3 activities have students work in groups to address a quantitative approach to experimental design and sampling. Adequate consideration of these issues is necessary to ensure microbial ecology experiments represent microbiology in "the real world." In the first exercise, students sample a simple community (composed of classroom materials), evaluate how much sampling is necessary, and quantify diversity using Simpson's index. The second activity is a simulated sampling exercise emphasizing spatial organization of microbes in the environment and its relationship to sampling methods. The third exercise addresses experimental design with an emphasis on designing correctly replicated experiments.