Shannon and Communication Theory

Introduction

This paper is intended to be a comprehensive analysis of Shannon's theory of communication, and its influence on a major emphasis area of communication studies -mass media communication. While the relevance of Shannon's work on professional communication shall be explicated in some detail; any coverage of his theory is incomplete without a complete analysis of how its acceptance totally revolutionized the art of media presentation and communication.

We first delimit our discussion to the emphasis area of mass media communication and summarize its history and scope - both present and future. This is followed by a description of Shannon's theory of communication and a comparison with other communication theories in terms of relative determinism and predictive power. We then describe the contexts in which it is primarily used and its underlying assumptions and concepts.

In the analytical portion of the paper, we discuss how Shannon's theory has become the fundamental precepts of advertising as well as its influence on other forms of professional communication viz. journalism and public relations. The influence of Shannon's work on the field of mass media is analyzed en passant.

Mass Media Studies

Mass media studies relate to aspects of communication theory that deal with the principles of attention, persuasion and credibility related to a large section of the population. In a world where freedom of expression is considered to be axiomatic, power rests in the hands of those who can influence the public voice. In consequence, mass media is occupying an ever increasing role in contemporary liberal societies.

The field of mass media communication is represented, in a classical sense, by advertising and journalism. With advances in technology, radio, TV, and most importantly, the Internet have repeatedly enhanced the power of these disciplines to shape public consciousness.

The fields of course, are as old as man itself: the first recorded instance being, of course, the well-documented case of the Serpent advertising the merits of the apple to Eve with, however, rather unfortunate results!

The first historical evidence of advertising is found on the walls of Pompeii, where commercial messages and even electoral campaign graffiti adorns the town walls. The first advertising agency was established by Volney Palmer in 1843. Today, advertising is an extremely scientific, lucrative and influential discipline.

Journalism shares its roots with advertising - in the broad sense of news-bearers, employed even by the ancient Greeks. The modern-day columnists are descended from the 18th century satirists - Addison, Defoe and Swift.

As Chomsky justly observes, the primary beneficiary of advancements in mass media communication is the controlling entity in a system. In an economy, the capitalist benefits; in a liberal democracy, the central government benefits; in a religion, the cult leaders benefit. Where there is a universal medium of expression that citizens can identify with, conformity in opinions and thought follow, leaving the masses amenable to influence and control.

Two historical examples of the importance of mass media may be found in the propaganda campaigns of the Bolsheviks at the time of the Russian revolution and Nazi propaganda during the Second World War. More whimsically, Orson Welles' alien invasion caper and its resultant panic are all too well-documented. Closer home, the White House's proclamation of the existence of weapons of mass destruction in Iraq galvanized public opinion to invade Iraq.

It is evident therefore, that mass media studies are extremely relevant to our cultural progress and that this emphasis area of communication theory will continue to influence the course of world affairs to an inordinately large extent. The ability to predict and modulate such an influence is then, a matter of great significance and value.

The entropy rate model

In his seminal 1948 publication "A Mathematical Theory of Communication", Claude Shannon brought about as cataclysmic a change in our perception of the nature of communication, as Einstein's Theory of Relativity had to our conception of our physical universe. By detaching the basis of communication from its semantic underpinnings, Shannon paved the way for the determination of accurate heuristics for predicting the efficacy of a medium of communication. In his introduction (Shannon 1948), he placed the model into perspective

The fundamental problem of communication is that of reproducing at one point either exactly or approximately a message selected at another point. Frequently the messages have meaning; that is they refer to or are correlated according to some system with certain physical or conceptual entities. These semantic aspects of communication are irrelevant to the engineering problem. The significant aspect is that the actual message is one selected from a set of possible messages. The system must be designed to operate for each possible selection, not just the one which will actually be chosen since this is unknown at the time of design.

Shannon considered a source of information which generates words composed of a finite number of symbols. These are transmitted through a channel, with each symbol spending a finite time in the channel. The problem involved statistics with the assumption that if xn is the nth symbol produced by the source, the xn process is a stationary stochastic process. He gave a method of analyzing a sequence of error terms in a signal to find their inherent variety, matching them to the designed variety of the control system.

The resulting idea of transmitting information as a series of 0s and 1s through a wire, while intuitively obvious today, was a surpassingly important an achievement in the progress of human intellectual thought. Slepian writes

Probably no single work in this century has more profoundly altered man's understanding of communication than C E Shannon's article, "A mathematical theory of communication", first published in 1948. The ideas in Shannon's paper were soon picked up by communication engineers and mathematicians around the world. They were elaborated upon, extended, and complemented with new related ideas. The subject thrived and grew to become a well-rounded and exciting chapter in the annals of science.

And if there can be any further tribute to Shannon's genius, it is that the