A computer-based tool for matching a site's characteristics with the appropriate model or models. This integrated system for model evaluation has three elements:
1. A selection system for use in choosing an exposure assessment model (currently for air, ground-water, nonpoint source, and surface water media models).
2. A validation database that includes information on models for air, ground-water, nonpoint source, and surface water assessment.
3. A model uncertainty database (currently only for six surface water models).
Each IMES element can be used independently. Once a model(s) has been selected, information on model uncertainty can be accessed.