Bestimmungsgröße

Bestimmungsgröße is a term used in German-language science to denote a quantity whose value determines or strongly influences the state, behavior, or outcome of a system. It functions as a parameter that fixes the conditions under which a model or experiment operates. In many contexts it is similar to a control parameter or driving variable, though its precise meaning can vary by field.

The concept is often contrasted with measured quantities (Messgrößen), which are observed or recorded rather than chosen to influence the system. A Bestimmungsgröße can be something that is set or constrained by the experimental setup, by theoretical assumptions, or by the model structure itself. Depending on the discipline, it may be treated as an independent variable, a conditioning parameter, or a principal factor that shapes results.

Examples appear across disciplines. In physics and chemistry, temperature can be a Bestimmungsgröße because it determines reaction rates or phase behavior under fixed pressure or concentration conditions. In ecology, the carrying capacity K of a population is a Bestimmungsgröße in logistic growth models, shaping the upper limit of abundance. In economics, price or policy levers can act as Bestimmungsgrößen that determine demand or equilibrium outcomes in a model.

Terminology and usage vary: some authors use Bestimmungsgröße interchangeably with terms like Bestimmungsparameter, Steuergröße, or Einflussgröße, while others prefer more specific labels such as independent variable or control parameter. The core idea is that a Bestimmungsgröße is a quantity that determines or largely governs the behavior of a system within a given framework.