Model corroboration refers to the quantitative and qualitative methods for evaluating the degree to which a model corresponds to reality. In some disciplines, this process has been referred to as validation. In general, the term "corroboration" is preferred by EPA because it implies a claim of usefulness and not truth. For more general information on how EPA develops and evaluates models, see the EPA document Guidance on the Development, Evaluation, and Application of Environmental Models. The linked copy includes some yellow highlighting of text used in this website for describing peer, verification, and corroboration reviews.

Model corroboration includes all quantitative and qualitative methods for evaluating the degree to which a model corresponds to reality. The rigor of these methods varies depending on the type and purpose of the model application. Quantitative model corroboration uses statistics to estimate how closely the model results match measurements made in the real system. Qualitative corroboration activities may include expert elicitation to obtain beliefs about a system's behavior in a data-poor situation.

For newly developed model frameworks or untested mathematical processes, formal corroboration procedures may be appropriate. Formal corroboration may involve formulation of hypothesis tests for model acceptance, tests on datasets independent of the calibration dataset, and quantitative testing criteria.

March 2024

• Georgia Institute of Technology performed a physical corroboration of the MCNP modeling used by the CPM calculator. In this study, experimental validation of gamma-ray detector efficiency responses was conducted for simulations of radiological external contamination from soil containing Cs-137. The study concluded that simulated total detection efficiency from energy deposition in the active volume of the detector crystal can be adopted for radionuclide screening purposes. The full report is available here.