Operational definition

An operational definition of a quantity is a specific process whereby it is measured. For example, the weight of an object can be operationally defined by using a balance and standard weights. Operational definitions are also used in defining system states by a specific preparation process. For example, 100 degrees Celsius can be crudely defined by the process of heating water until it is observed to boil.

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

It has been said, slightly imprecisely, that the operational definition of a cake is the recipe for baking the cake, which we can regard as a state preparation process. A similar saying, if it walks like a duck and quacks like a duck, it's a duck, can be regarded as a sort of measurement process.

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

Despite the controversial philosophical origins of the concept, particularly its close association with logical positivism, operational definitions have undisputed practical applications. Operational definitions are particularly important in quantum mechanics, statistical physics and relativity.

Related Topics:
Philosophical - Logical positivism - Quantum mechanics - Statistical physics - Relativity

~ ~ ~ ~ ~ ~ ~ ~ ~ ~