Communication theory is a field of information and mathematics that studies the technical
process of information and the human process of human communication.
According to communication theorist Robert T. Craig in his essay "Communication Theory
as a Field", "despite the ancient roots and growing profusion of theories about communication",
there is not a field of study that can be identified as "communication theory".
History
Origins "The fundamental problem of communication
is that of reproducing at one point either exactly or approximately a message selected
at another point."
Claude Shannon The origins of communication theory is linked
to the development of information theory in the early 1920s.
Limited information-theoretic ideas had been developed at Bell Labs, all implicitly assuming
events of equal probability.
Harry Nyquist's 1924 paper, Certain Factors Affecting Telegraph Speed, contains a theoretical
section quantifying "intelligence" and the "line speed" at which it can be transmitted
by a communication system.
Ralph Hartley's 1928 paper, Transmission of Information, uses the word "information" as
a measurable quantity, reflecting the receiver's ability to distinguish one sequence of symbols
from any other.
The natural unit of information was therefore the decimal digit, much later renamed the
hartley in his honour as a unit or scale or measure of information.
Alan Turing in 1940 used similar ideas as part of the statistical analysis of the breaking
of the German second world war Enigma ciphers.
The main landmark event that opened the way to the development of communication theory
was the publication of an article by Claude Shannon in the Bell System Technical Journal
in July and October 1948 under the title "A Mathematical Theory of Communication".
Shannon focused on the problem of how best to encode the information that a sender wants
to transmit.
He used also tools in probability theory, developed by Norbert Wiener.
They marked the nascent stages of applied communication theory at that time.
Shannon developed information entropy as a measure for the uncertainty in a message while
essentially inventing the field of information theory.
In 1949, in a declassified version of his wartime work on the mathematical theory of
cryptography, he proved that all theoretically unbreakable ciphers must have the same requirements
as the one-time pad.
He is also credited with the introduction of sampling theory, which is concerned with
representing a continuous-time signal from a discrete set of samples.
This theory was essential in enabling telecommunications to move from analog to digital transmissions
systems in the 1960s and later.
In 1951, Shannon made his fundamental contribution to natural language processing and computational
linguistics with his article "Prediction and Entropy of Printed English", providing a clear
quantifiable link between cultural practice and probabilistic cognition.
Models of communication
The studies on information theory by Claude Elwood Shannon, Warren Weaver and others,
prompted research on new models of communication from other scientific perspectives like psychology
and sociology.
In science, a model is a structure that represents a theory.
Scholars from disciplines different from mathematics and engineering began to take distance from
the Shannon and Weaver models as a 'transmissible model':
They developed a model of communication which was intended to assist in developing a mathematical
theory of communication.
Shannon and Weaver's work proved valuable for communication engineers in dealing with
such issues as the capacity of various communication channels in 'bits per second'.
It contributed to computer science.
It led to very useful work on redundancy in language.
And in making 'information' 'measurable' it gave birth to the mathematical study of 'information
theory' — D. Chandler,
Harold Lasswell, a political scientist and communication theorist, was a member of the
Chicago school of sociology.
In his work "The Structure and Function of Communication in Society", he defined the
communication process as "Who What Whom What Channel What Effect".
The distinct model he propounded was known as Dance Model.
These first studies on communication's models promoted more researches on the topic.
Wilbur Lang Schramm, whom communication theorist Everett Rogers called the "founder of communication
study", focused his studies on the experience of the sender and receiver.
Communication is possible only upon a common language between sender and receiver.
Everett Roger's accounts later led to the basis for development communication studies.
In 1960, David Kenneth Berlo, a disciple of Schramm, expanded on Shannon and Weaver's
linear model of communication and created the Sender-Message-Channel-Receiver Model
of communication exposed in his work The Process of Communication, where communication appears
as a regulated process that allows the subject to negotiate with his living environment.
Communication becomes, then, a value of power and influence.
In 1963, Richard Whately's "Elements of Rhetoric" was republished with a critical introduction
by Douglas Ehninger and a foreword by David Potter.
They explored what they called the "Aristotle's models of communication".
James L. Kinneavy also explored Aristotle's rhetoric and communication model in "A Theory
of Discourse".
"Communication Theory as a Field"
In 1999, Craig wrote a landmark article, "Communication Theory as a Field", which expanded the conversation
regarding disciplinary identity in the field of communication.
At that time, communication theory textbooks had little to no agreement on how to present
the field or what theories to include in their textbooks.
This article has since become the foundational framework for four different textbooks to
introduce the field of communication.
In this article, Craig "proposes a vision for communication theory that takes a huge
step toward unifying this rather disparate field and addressing its complexities."
To move toward this unifying vision, Craig focused on communication theory as a practical
discipline and shows how "various traditions of communication theory can be engaged in
dialogue on the practice of communication."
In this deliberative process, theorists would engage in dialog about the "practical implications
of communication theories."
In the end, Craig proposes seven different traditions of communication theory and outlines
how each one of them would engage the others in dialogue.
Elements of communication Basic elements of communication made the object
of study of the communication theory: Source: Shannon calls this element the "information
source", which "produces a message or sequence of messages to be communicated to the receiving
terminal."
Sender: Shannon calls this element the "transmitter", which "operates on the message in some way
to produce a signal suitable for transmission over the channel."
In Aristotle, this element is the "speaker".
Channel: For Shannon, the channel is "merely the medium used to transmit the signal from
transmitter to receiver."
Receiver: For Shannon, the receiver "performs the inverse operation of that done by the
transmitter, reconstructing the message from the signal."
Destination: For Shannon, the destination is "the person for whom the message is intended".
Message: from Latin mittere, "to send".
The message is a concept, information, communication, or statement that is sent in a verbal, written,
recorded, or visual form to the recipient.
Feedback Entropic elements, positive and negative
See also In semiotics, there are more elaborated models
and theories of communication from a linguistic and philosophical point of view.
Metacommunicative competence Rogerian argument
Tetrad of media effects Text and conversation theory
References
Further reading
External links American Communication Association
Central States Communication Association Eastern Communication Association
International Communication Association National Communication Association
Southern States Communication Association Western States Communication Association