Nothing could be more effective than a wilderness experience to demonstrate the importance of conserving biodiversity. When that is not possible, though, there are computer models with several features that are helpful in understanding how biodiversity is measured. These models are easily used when natural resources, transportation, and time constraints limit the use of field laboratories. Moreover, computer models can generate realistic data, in large quantities, that can be used to calculate different indices of diversity. In this article, the authors provide background on concepts and measures of biodiversity, and present two agent-based simulation models that can be accessed from the Internet. One model simulates stream sampling for invertebrate biodiversity, while the other simulates sampling for plant diversity. The stream sampling model is simpler, and effective as a demonstration as well as for generating data for analysis. It is designed to be used at the high school and college levels. The plant sampling model is more advanced, and is useful in teaching experimental design and to generate data for advanced analyses. It is appropriate for the college level, or AP biology. (Contains 3 figures and 6 tables.)