Models
Terms
Misc
100
In these models, the structure is determined by the observed statistical relationship among experimental data. These models can be used to develop relationships that are useful for forecasting and describing trends in behavior, but they are not necessarily mechanistically relevant - that is, they don’t explain the real causes and mechanisms for the relationships.
What is the Empirical Model
100
The degree to which the model outputs are affected by changes in selected input parameters
What is Sensitivity
100
Answers the questions: “Is the science valid and does the model use current methods and techniques? Is the numerical model adequate to convey the science principles at the level of the question being asked? Is the model arriving at an acceptably accurate representation of the phenomenon being modeled?"
What is Validation
200
A model that includes variability in model parameters. This variability is a function of: 1) changing environmental conditions, 2) spatial and temporal aggregation within the model framework, 3) random variability. The solution obtained by the model or output is therefore a function of model components and random variability.
What is the Stochastic Model
200
A set of rules for solving some problem. On a computer, an algorithm is a set of rules in computer code that solve a problem.
What is an Algorithm
200
A measured or estimated quantity which describes an object or can be observed in a system and which is subject to change
What is Variable
300
Models obtained by fitting observational data to a mathematical function
What are Statistical Models
300
Terms in the model that are fixed during a model run or simulation but can be changed in different runs as a method for conducting sensitivity analysis or to achieve calibration goals
What are Parameters
300
A model that provides a single solution for the variables being modeled. Because this type of model does not explicitly simulate the effects of data uncertainty or variability, changes in model outputs are solely due to changes in model components.
What is the Deterministic Model
400
A hypothesis regarding the important factors that govern the behavior of an object or process of interest. This can be an interpretation or working description of the characteristics and dynamics of a physical system.
What is the Conceptual Model
400
The process of adjusting model parameters within physically defensible ranges until the resulting predictions give the best possible fit to the observed data
What is Calibration
400
Answers the questions: "Does the code for the model run correctly and provide a mathematically correct answer? Do the algorithms being used accurately represent the mathematical function on the computer?"
What is Verification
500
A model based on the underlying mathematical formulation for the general linear function Y = ax +b which will form a straight line when graphed
What is a Linear Model
500
The closeness of a measured or modeled/computed value to its “true” value. The “true” value is the value it would have if we had perfect information.
What is Accuracy
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