Mesures

Mesures is the plural of the French noun mesure, meaning measurements or measures. In common use, it denotes both the process of measuring and the quantities obtained, as well as formal actions or instruments aimed at influencing or regulating a system.

In science and engineering, measurement is the assignment of a numerical value to a property. It relies on standardized units, instruments, and calibration. Measurements have associated uncertainty and are traceable to reference standards. Direct measurements yield a quantity immediately; indirect measurements infer a quantity from related observations.

In public policy and governance, measures refer to actions enacted to achieve objectives: fiscal measures, environmental measures, public health measures, security measures. They can be regulatory, economic, informational, or infrastructural, and are evaluated on effectiveness, cost, and equity.

In mathematics, measure theory defines a measure as a function μ from a sigma-algebra to [0, ∞] with μ(∅)=0 and countable additivity. The Lebesgue measure on Euclidean space is a central example, enabling integration and probability. Other measures include Borel, Radon, and probability measures.

Etymology and usage: from Old French mesur, mesurer, from Latin mensura. In many languages, "mesures" is used to denote measurement results or steps such as policy measures; in English, the term appears mainly in mathematical or historical contexts when referencing French terminology or texts.