In this section we want to clarify what are the Communication Sciences (which from now on I will call "Communication Science" - with no "s"), by giving a definition of it. To this aim, we should first clarify what is meant by the communication system. Simply, a communication system is a set of subsystems that we will call communicative units. Each communicative unit interacts/communicates with the outside world and, depending on the interactions, changes its physical state. For example, a communication system can be made up of a light bulb and a switch. The bulb is a communication unit whose state has two possible values: on or off, and this value can change depending on the message communicated by the switch. Similarly to the definition of the Object Oriented Programming paradigm, for what interests us, we give the following definitions:
"Object" Definition: an object is a particular set of properties/attributes, each of which takes a value in a set of possible values.
Definition of "Object state": the state of an object is a set of values assumed by the properties of the object.
For example, an object can be "my car" (or rather, a particular (may be, simple) schematization/model of my car) which is characterized by particular set of attributes such as the Brand, the Model, the Color, the Production year, the Plate and the Mileage. Each one of the attributes has a value in a set of possible values (say, Brand = OPEL, Model = CORSA, Color = BLUE, Production year = 2001, Plate = BZ234KM and Mileage = 324556). One state of the "My Car" is then
(Brand, Model, Color, Production year, Plate,Mileage)=(OPEL, CORSA, BLUE, 2001, BZ234KM, 324556).
However, other possible states are:
(Brand, Model, Color, Production year, Plate,Mileage)=(OPEL, CORSA, BLUE, 2001, BZ234KM, 30021),
(Brand, Model, Color, Production year, Plate,Mileage)=(OPEL, CORSA, RED, 2001, BZ234KM, 324556),
(Brand, Model, Color, Production year, Plate,Mileage)=(OPEL, CORSA, RED, 2001, AB320BE, 12345).
Definition of "Communication unit/entity": a communication unit is an object which, depending on an input message (for example, a sequence of 0s and 1s), possibly changes state and gives an output message.
Definition of "State of a Communication unit": the state of a communication unit is a set of values assumed by the properties of the system considered as an object.
For example, the object "my car" above is a system that once has received the message defined by the sequence of actions of engine start and set in motion, it changes state so that, for example, the Mileage increases. We can imagine that the communication world consists of a set of systems (which are the schematizations representing the constituent entities of reality such as men, automobiles, animals, computers, etc.) that interact with each other by exchanging messages so that each one tries to change the status of some others for certain purposes. We call "Communication system" this set of systems that communicate with each other. So, we give the following:
Definition of "Communication system": a Communication system is a set of Communication units that communicate with each other.
Definition of "Communication science": The Communication science is the science that deals with analyzing Communication systems. In particular, it deals with what information/message (say, sequence of 0 and 1) is to be transmitted to receiving communication units so that they go/remain in a given state fixed a priori.
Note that in this model, if the receiving system is a human being (or its schematization) then the social subject of Communication Science is the art of transmitting messages to the receivers so that they go into a wanted (for example, mental) state. Think about the advertising, the teching communication, the artistic communication, and so on. Note also that the rules by which a message induces a state change in the receiving entity may be more or less known. In the case, these rules are not all known, then the problem of finding what message to send to a system so that to induce a particular state becomes in a way a cryptanalysis problem.