Sensitivity Analysis (Model)

{
  "id": "MLC-T-ENV-025227",
  "term": "Sensitivity Analysis (Model)",
  "field": "Environment",
  "definition": "1. The computation of the effect of changes in input values or assumptions (including boundaries and model functional form) on the outputs (Morgan and Henrion 1990); the study of how uncertainty in a model output can be systematically apportioned to different sources of uncertainty in the model input (Saltelli et al. 2000a). By investigating the “relative sensitivity” of model parameters, a user can become knowledgeable of the relative importance of parameters in the model.\n\n2. A method used to examine the behavior of a model by measuring the variation in its outputs resulting from changes to its inputs. [CAC 1999, FAO/WHO 2003b]\n\n3. Process for identifying the important sources of variability and uncertainty in a model’s output. Different techniques can be used in each of the 3 tiers of the tiered process for PRA. In Tier 1, sensitivity ratios are used to quantify the effects of changes in one or more model inputs on the model output. In Tiers 2 and 3, correlation analysis can be used to rank inputs based on their relative contribution to variance in risk. Local sensitivity refers to nominal changes in inputs within a plausible range, whereas range sensitivity refers to changes in inputs across the minimum and maximum values of the plausible range.\n\n4. The computation of the effect of changes in input values or assumptions (including boundaries and model functional form) on the outputs. The study of how uncertainty in a model output can be systematically apportioned to different sources of uncertainty in the model input. By investigating the “relative sensitivity” of model parameters, a user can become knowledgeable of the relative importance of parameters in the model.\n\n5. Process of changing one variable while leaving the others constant to determine its effect on the output. This procedure fixes each uncertain quantity at its credible lower and upper bounds (holding all others at their nominal values, such as medians) and computes the results of each combination of values. The results help to identify the variables that have the greatest effect on exposure estimates and help focus further information gathering efforts. [EPA 1997a]",
  "references": [
    "EPA Guidance on the Development, Evaluation and Application of Environmental Models EPA/100/K-09/003 | March 2009 at http://www.epa.gov/crem/library/cred_guidance_0309.pdf",
    "MRA Thesaurus",
    "EPA Definitions of Terms Relevant to PRA and References for Further Reading at http://www.epa.gov/oswer/riskassessment/rags3adt/pdf/appendixe.pdf",
    "Modeling Glossary"
  ],
  "url": "https://mlchart.com/terminology/environment/sensitivity-analysis-model/"
}