Types of Models in Mathematical Modeling
Mathematical models can be categorized in various ways, depending on their characteristics. Here are some common types of models:
Deterministic Models
A deterministic model is one in which every set of variable states is uniquely determined by parameters in the model and by sets of previous states of these variables. Therefore, a deterministic model always performs the same way for a given set of initial conditions.
Stochastic Models
Unlike deterministic models, stochastic models incorporate an element of randomness. They are used when the modeler accepts that perfect, deterministic knowledge of a system is impossible, and chooses instead to model it in a way that accounts for likely variations.
Static Models
Static models do not take into account the element of time. They represent a snapshot of the system at a particular point in time.
Dynamic Models
Dynamic models, on the other hand, do consider how things change over time. They may be deterministic or stochastic, and they represent systems as they change.
Linear Models
In linear models, the output variables are always linear functions of the input variables.
Nonlinear Models
Nonlinear models, by contrast, have output variables that change non-linearly with the input variables.
Discrete Models
Discrete models are used when the variables represent counts such as the number of individuals in a population. They describe systems where changes occur at distinct, separate points in time.
Continuous Models
Continuous models describe systems where changes occur over a continuum, often time. These models often involve rates of change, such as speed or population growth rate, that vary continuously.
Empirical Models
Empirical models are based on observations and experimental data. These models do not necessarily have theoretical or conceptual bases but are nonetheless useful for making predictions or identifying relationships between variables.
Theoretical Models
Theoretical models are developed based on theory rather than direct observation. They often involve a considerable amount of abstraction and simplification, depending on the complexity of the system being modeled.
Remember that all models, regardless of their type, are simplifications of the real-world systems they represent. The best type of model to use depends on the specific context and goals of the modeling effort.