DAVID P. LARSEN,^* THOMAS M. KINCAID,^** STEVEN E. JACOBS,^*** N. SCOTT URQUHART<sup>****


*</sup>David P. Larsen (larsen.david@epa.gov), whose research interests are survey designs and the variability structure of lake and stream indicators, is an aquatic biologist with the US Environmental Protection Agency's Environmental Monitoring and Assessment Program, 200 SW 35th Street, Corvallis, OR 97333.
^**Thomas M. Kincaid, whose research interests include analysis of responses of biological indicators to environmental gradients, is a statistician with Dynamac International Corporation, also in Corvallis, OR.
^***Steven E. Jacobs is a fisheries biologist who oversees the Oregon Department of Fish and Wildlife coho spawning surveys in Oregon's coastal streams; his address is 28655 Highway 34, Corvallis, OR 97333.
^****N. Scott Urquhart, a professor of statistics at Colorado State University, Ft. Collins, CO 80523, has broad interests in the application of statistical theory to environmental problems, including survey designs, analysis of variance, and relationships among ecological attributes.