interparameter

Interparameter is a term used to describe a parameter that quantifies the interaction or coupling between two or more other parameters within a system or model. It is employed to capture how the effect of one parameter on an outcome changes depending on the level or state of another parameter. Although not universally standardized, interparameter appears in discussions of interaction effects, cross-terms, and parameter coupling across various disciplines.

In statistical modeling, interparameters commonly appear as interaction terms. For example, in a linear model such as y = β0 + β1x1 + β2x2 + γx1x2, the coefficient γ acts as an interparameter that measures how the combined presence of x1 and x2 influences the response beyond their individual effects. In this sense, γ is often referred to as an interaction parameter. Similar concepts occur in experimental design and multivariate analysis, where interaction or cross-terms reveal dependencies between factors.

In physics and engineering, interparameters can describe coupling constants or other parameters that link two fields or subsystems. Such parameters quantify the strength or manner of interaction, and their estimation often relies on data that vary together across the interacting factors.

Estimating interparameters requires careful model specification and sufficient data on the combinations of involved parameters. They can improve explanatory power but may introduce identifiability and multicollinearity concerns. Interparameters are distinguished from main parameters by their role in representing interdependencies rather than individual, independent effects. See also: interaction term, coupling parameter.