MnModel's predictive power has improved through the successive phases of the project. These improvements have been achieved by better data and refined modeling procedures.
Phase 1 models (1996) were developed for only 27 counties. They predict sites 22%-54% better than by random chance alone.
Phase 2 models (1997) were developed for the entire state. They predict sites 28%-89% better than by random chance alone.
Phase 3 incorporated information about the likelihood of surveys into the predictive models. The Phase 3 Survey Implementation Model (1998) predicts sites 44%-90% better than by random chance alone. It also indicates areas where the potential for sites is unknown because of inadequate survey information.
Phase 4 is in progress. Environmental and archaeological data have been updated, new environmental data have become available, new statistical methods have been developed, and models of prehistoric/historic surface hydrography have been created.