proportionalonly

Proportionalonly is a term used in some technical contexts to denote an approach, model, or system that relies exclusively on proportional relationships between variables. It is not a formally standardized concept, but a descriptive label applied in fields such as control theory, statistics, and political science.

In control theory, proportional-only control refers to a controller whose output is strictly proportional to the current error signal, commonly written as u(t) = Kp e(t). Such a controller is simple and fast, but may exhibit steady-state error and reduced robustness to disturbances because it lacks integral action.

In statistics and data modeling, proportionalonly can describe models or weighting schemes that use only proportional effects of predictors. For example, a proportional-only regression might omit intercept terms or constrain coefficients to reflect proportional contributions of inputs to the response. In practice, this can lead to biased fits unless the data are centered or the model is properly specified.

In electoral contexts, proportional-only can describe a pure proportional representation system, where seats are allocated strictly in proportion to votes, without winner-take-all districts or bonus seats. In practice, many real-world systems combine proportional weighting with other rules to address thresholds, district magnitude, or governance stability.

Limitations and notes: The approach can be sensitive to scale and outliers; in many domains, proportional-only methods are insufficient without supplementary mechanisms to handle nonproportional effects.

See also: proportional representation, PID controller, linear regression, weighting schemes.