parametre

Parametre, also written parameter in English and paramètre in French, is a quantity that helps define or constrain the behavior of a mathematical model, function, or physical system. In mathematics, a parameter is typically treated as a constant within a problem, while the variables of interest change with the input. A family of curves such as y = f(x; p) is generated by varying the parameter p. In statistics, a parameter describes a population characteristic and is fixed but usually unknown; common examples include the population mean μ and variance σ^2. The term derives from Greek para- “beside” and metron “measure.”

In computing and programming, parameter has a related but distinct sense. A formal parameter is a variable in a function definition that receives a value when the function is called, whereas the actual parameter (argument) is the value supplied at the call site. This distinction helps separate a function’s interface from its inputs and allows code to be more general and reusable.

In applied fields, parameters appear in models, experiments, and designs. They can be fixed constants or quantities to be estimated from data, a process known as parameter estimation or calibration. Sensitivity analysis examines how changes in parameters affect outcomes. Design parameters are choices that define a system’s architecture or constraints, such as dimensions, tolerances, or operating conditions. Across disciplines, identifying and interpreting parameters is essential for modeling, prediction, and control.