1. 1  the region below the lithosphere, variously estimated as being from fifty to several hundred miles (eighty-five to several hundred kilometers) thick, in which the rock is less rigid than that above and below but rigid enough to transmit transverse seismic waves.
Operationalization is sometimes used to specifically refer to the scientific practice of operationally defining, where even the most basic concepts are defined through the operations by which we measure them. This comes from the work of Percy Williams Bridgman, whose methodological position is called operationalism.
Thus, some phenomena are directly difficult to observe (i.e. they are latent), but their existence can be inferred by means of their observable effects. The concept of operationalization was first presented by the British physicist N. R. Campbell in his 'Physics: The Elements' (Cambridge, 1920).