From Wikipedia: "An '''operational definition''' is the application of operationalization used in defining the terms of a process needed to determine the nature of an item or phenomenon and its properties such as duration, quantity, extension in space, chemical composition, etc. The procedures included in definitions should be repeatable by anyone or at least by peers. An example of operational definition of the term ''weight'' of an object, operationalized to a degree, would be the following: "weight is the numbers that appear when that object is placed on a weighing scale. According to it, the weight can be any of the numbers shown on the scale after, including the very moment the object is put on it. Clearly, the inclusion of the moment when one can start reading the numbers on the scale would make it more fully an operational definition. Nonetheless, it is still in contrast to those purely theoretical definitions.
In this video we argue about the need for operational definitions in information security.