Models of communication
Fragmentation and problems of interdisciplinary outlook have generated a wide range of discussion concerning the ways in which communication occurs and the processes it entails. Most speculation on these matters admits, in one way or another, that the communication theorist’s task is to answer as clearly as possible the question, “Who says what to whom with what effect?” (This query was originally posed by the U.S. political scientist Harold D. Lasswell.) Obviously, all the critical elements in this question may be interpreted differently by scholars and writers in different disciplines.
Linear models
One of the most productive schematic models of a communications system that has been proposed as an answer to Lasswell’s question emerged in the late 1940s, largely from the speculations of two American mathematicians, Claude Shannon and Warren Weaver. The simplicity of their model, its clarity, and its surface generality proved attractive to many students of communication in a number of disciplines, although it is neither the only model of the communication process extant nor is it universally accepted. As originally conceived, the model contained five elements—an information source, a transmitter, a channel of transmission, a receiver, and a destination—all arranged in linear order. Messages (electronic messages, initially) were supposed to travel along this path, to be changed into electric energy by the transmitter, and to be reconstituted into intelligible language by the receiver. In time, the five elements of the model were renamed so as to specify components for other types of communication transmitted in various manners. The information source was split into its components (both source and message) to provide a wider range of applicability. The six constituents of the revised model are (1) a source, (2) an encoder, (3) a message, (4) a channel, (5) a decoder, and (6) a receiver. For some communication systems, the components are as simple to specify as, for instance, (1) a person on a landline telephone, (2) the mouthpiece of the telephone, (3) the words spoken, (4) the electrical wires along which the words (now electrical impulses) travel, (5) the earpiece of another telephone, and (6) the mind of the listener. In other communication systems, the components are more difficult to isolate—e.g., the communication of the emotions of a fine artist by means of a painting to people who may respond to the message long after the artist’s death.
Begging a multitude of psychological, aesthetic, and sociological questions concerning the exact nature of each component, the linear model appeared, from the commonsense perspective, at least, to explain in general terms the ways in which certain classes of communication occurred. It did not indicate the reason for the inability of certain communications—obvious in daily life—to fit its neat paradigm.
Entropy, negative entropy, and redundancy
Another concept, first called by Shannon a noise source but later associated with the notion of entropy (a principle derived from physics), was imposed upon the communication model. Entropy is analogous in most communication to audio or visual static—that is, to outside influences that diminish the integrity of the communication and, possibly, distort the message for the receiver. Negative entropy may also occur in instances in which incomplete or blurred messages are nevertheless received intact, either because of the ability of the receiver to fill in missing details or to recognize, despite distortion or a paucity of information, both the intent and content of the communication.
Although rarely shown on diagrammatic models of this version of the communication process, redundancy—the repetition of elements within a message that prevents the failure of communication of information—is the greatest antidote to entropy. Most written and spoken languages, for example, are roughly half-redundant. If 50 percent of the words of this article were taken away at random, there would still remain an intelligible—although somewhat peculiar—essay. Similarly, if one-half of the words of a radio news commentator are heard, the broadcast can usually be understood. Redundancy is apparently involved in most human activities, and, because it helps to overcome the various forms of entropy that tend to turn intelligible messages into unintelligible ones (including psychological entropy on the part of the receiver), it is an indispensable element for effective communication.
Messages are therefore susceptible to considerable modification and mediation. Entropy distorts, while negative entropy and redundancy clarify; as each occurs differentially in the communication process, the chances of the message being received and correctly understood vary. Still, the process (and the model of it) remains conceptually static, because it is fundamentally concerned with messages sent from point to point and not with their results or possible influences upon sender and receiver.
Feedback
To correct this flaw, the principle of feedback was added to the model and provided a closer approximation of interpersonal human interaction than was known theretofore. This construct was derived from the studies of Norbert Wiener, the so-called father of the science of cybernetics. Wiener’s cybernetic models, some of which provide the basis for current computer technology, were designed to be responsive to their own behaviour; that is, they audited their own performances mathematically or electronically in order to avoid errors of entropy, unnecessary redundancy, or other simple hazards.
Certain types of common communications—holiday greeting cards, for instance—usually require little feedback. Others, particularly interactions between human beings in conversation, cannot function without the ability of the message sender to weigh and calculate the apparent effect of his words on his listener. It is largely the aspect of feedback that provides for this model the qualities of a process, because each instance of feedback conditions or alters the subsequent messages.
