Based on material developed by the Save Our Streams program (Izaak Walton League of America), this educational resource on streams is provided by the University of Virginia at Charlotteville. The Stream Study homepage is an online guide for determining the water quality of streams, based on collecting and identifying stream-bottom macroinvertebrates (e.g., crayfish, mussels, and larvae of aquatic insects). The resource includes an illustrated identification key for "common stream-bottom macroinvertebrates;" a classification of macroinvertebrates based on sensitivity to "pollution;" practice samples (to test your recently acquired knowledge); a glossary of terms; sampling procedures and forms; and links to additional information. Although the classification scheme presented here (re. pollution sensitivity) raises skepticism among some scientists, the resource is still worthwhile. Educators could use this information to create lab exercises, raise interesting points of discussion, and guide users through hands-on field/ lab experiences.