Measurement

Measurement is a fundamental process aimed at producing objective and intersubjective information about empirical properties of objects in the form of values of properties. The history of measurement, from antiquity to the present, can be viewed as the development of a consistent interpretation of this position. In the classical era, measurement was understood based on a realist perspective, according to which the aim of such a process is to determine the ratio that is assumed to exist between the quantity to be measured and a quantity of the same kind, chosen as a unit. In the modern era, a more refined understanding was progressively developed, thanks to the improvements elicited by the operationalist account of the notion of measurable quantity and the representationalist emphasis on the conditions that empirical properties must satisfy to be meaningfully representable in terms of numerical values. In the present days, these perspectives are incorporated into a model-based account of measurement, focused both on highlighting how models enter the understanding of objects and their properties and on characterizing measurement accordingly. This chapter aims at presenting the main ideas involved in the historical development of the aforementioned perspectives, specifically in relation to the way they interpret the measurement equation, i.e., the relation between the quantity intended to be measured and the measured value.