Some have suggested that the very common practice of beginning a communication theory class with an attempt to define communication and theory is flawed pedagogy. Nonetheless, it is difficult to begin a study of the theories of communication without first having some grasp, however temporary and tenuous, of what sorts of phenomena "count" as communication, and what kinds of ideas about those phenomena constitute "theory," or, more specifically, good theory.S

Communication is a slippery concept, and while we may casually use the word with some frequency, it is difficult to arrive at a precise definition that is agreeable to most of those who consider themselves communication scholars. Communication is so deeply rooted in human behaviors and the structures of society that it is difficult to think of social or behavioral events that are absent communication.

We might say that communication consists of transmitting information from one person to another. In fact, many scholars of communication take this as a working definition, and use Lasswell's maxim ("who says what to whom to what effect") as a means of circumscribing the field of communication. Others suggest that there is a ritual process of communication that cannot be artificially abstracted from a particular historical and social context. As a relatively young field of inquiry, it is probably premature to expect a conceptualization of communication that is shared among all or most of those who work in the area. Furthermore, communication theory itself is, in many ways, an attempt to describe and explain precisely what communication is.

Indeed, a theory is some form of explanation of a class of observed phenomena. Karl Popper colorfully described theory as "the net which we throw out in order to catch the world--to rationalize, explain, and dominate it." The idea of a theory lies at the heart of any scholarly process, and while those in the social sciences tend to adopt the tests of a good theory from the natural sciences, many who study communication adhere to an idea of communication theory that is akin to that found in other academic fields.

This book approaches communication theory from a biographical perspective, in an attempt to show theory development within a social context. Many of these theorists would not actually consider themselves "communication" researchers. The field of communication study is remarkably inclusionary, and integrates theoretical perspectives originially developed in a range of other disciplines.

see: http://en.wikibooks.org/wiki/Communication_Theory