Model

{
  "id": "MLC-T-ENV-017602",
  "term": "Model",
  "field": "Environment",
  "definition": "1. A simplification of reality that is constructed to gain insights into select attributes of a physical, biological, economic, or social system. A formal representation of the behavior of system processes, often in mathematical or statistical terms. The basis can also be physical or conceptual.\n\n2. A mathematical function with parameters that can be adjusted so the function closely describes a set of empirical data. A mechanistic model usually reflects observed or hypothesized biological or physical mechanisms, and has model parameters with real world interpretation. In contrast, statistical or empirical models selected for particular numerical properties are fitted to data; model parameters may or may not have real world interpretation. When data quality is otherwise equivalent, extrapolation from mechanistic models (e.g., biologically based dose-response models) often carries higher confidence than extrapolation using empirical models (e.g., logistic model).\n\n3. Any representation of a system by something other than the system itself.\n\n4. \"Model\" is the name of the vehicle. In some cases, manufacturers subdivide a model according to various trim levels which do not affect the emissions or fuel economy levels. Not all of these model name subdivisions may appear in the Guide, but the emissions and fuel economy will be the same.\n\n5. A system of mathematical expressions that describe and represent the physical world or some aspect therein. In the Bay Total Maximum Daily Load (TMDL), models are used to describe both hydrologic and water quality processes as well as estimate the load of a specific pollutant to a water body and make predictions about how the load would change as remediation methods (e.g. scenarios) are implemented.\n\n6. A representation of an environmental system obtained through the use of mathematical equations or relationships.\n\n7. A mathematical representation of a natural system intended to mimic the behavior of the real system, allowing description of empirical data and predictions about untested states of the system.\n\n8. A mathematical statement of the relation(s) among variables. Models can be of two basic types, or have two basic parts: statistical models, which predict a measured quantity; probability models, which predict the relative frequency of different random outcomes.\n\n9. Computer representation of environmental systems, problems or solutions.\n\n10. A mathematical function with parameters that can be adjusted so the function closely describes a set of empirical data. A mechanistic model usually reflects observed or hypothesized biological or physical mechanisms, and has model parameters with real world interpretation. In contrast, statistical or empirical models selected for particular numerical properties are fitted to data; model parameters may or may not have real world interpretation. When data quality is otherwise equivalent, extrapolation from mechanistic models (e.g., biologically based dose-response models) often carries higher confidence than extrapolation using empirical models (e.g., logistic model). [EPA 2003]\n\n11. A simplified representation, either mathematical or physical, of a real system. \"Model\" the word is often used as the noun (the representation), but may also be used as the verb (to make the representation.).",
  "subject": "Science and research",
  "references": [
    "Modeling Glossary",
    "Integrated Risk Information System (IRIS) Glossary; EPA 2003",
    "Urban Watershed Management Research Terminology; Urban Watershed Glossary",
    "Green Vehicle Guide Glossary",
    "Chesapeake Bay TMDL Glossary",
    "Watershed Planning Glossary of Terms",
    "Benchmark Dose Software (BMDS) Glossary of Terms; EPA 2004",
    "NIST/SEMATECH 2005b",
    "Reusable Component Services (RCS) Glossary; RCS Glossary",
    "Thesaurus of Terms Used in Microbial Risk Assessment",
    "EPA EV-Research-Research Resources-Model & Simulation Tools"
  ],
  "url": "https://mlchart.com/terminology/environment/model/"
}