Ecoregional Assessment is a method for setting geographic priorities based on the status of biodiversity, habitat condition, threats and socio-political conditions in an ecoregion.  Because TNC has a long history of conducting ecoregional assessments, we have a lot of material available on this approach.  

In more detail, ecoregional assessments use ecoregions as the unit of analysis. For an ecoregion or collection of ecoregions we develop and disseminate finer-scale data on the distribution and status of biodiversity, habitat condition, current and future threats and the socio-political conditions that influence conservation success within those ecoregions. These finer-scale data allow us to set long-term conservation goals for ecosystems, natural communities and imperiled or declining species representative of an ecoregion, and to establish ecoregional priorities for resource allocation — specific landscapes, threats to biodiversity and strategic opportunities that affect one or more ecoregions and demand immediate attention. Ecoregional data also provide a baseline against which we can measure progress toward our mission at the level of the ecoregion, as well as toward the long-term goals for the representative ecosystems and species within an ecoregion.