"My earliest contact with modern scientific philosophy may have been P.W Bridgman's concept of "operational definition" (Bri 27). An operational definition of anything is a precise sequence of physical operations that enable one to either construct it or identify it with certainty. When one can't make an operational definition of something, this is usually an indication of poor understanding of it. Attempts to operationalize definitions can be guides to discovery I've found this idea to be an invaluable tool in telling me whether or not I really understand something. Though individual concepts in a theory need not be operational, the theory as a whole must have operational meaning. Rapoport (Rap 53) discusses the application of operational concepts in daily life as well in science" from Solomonoff's