The Ecological Risk Assessment Research Review Subcommittee's major conclusion was that the overall concept of ecological risk assessment developed in the program is comprehensive, scientifically ambitious, and sets forth a research direction for the long-term (perhaps twenty years). In the short-term (five-year), it is not achievable as planned, particularly because some of the key elements (density-dependent population, community and ecosystem mechanistic models) are based on an incomplete understanding of the fundamental mechanisms. However, the research staff have made a promising start in identifying some of the major issues the program should address.