Communication occurs only when there are two associated information producing processes and the output from one process is the functional inverse of the other process's output. We can say that communication occurred and that information was transferred between the input to the first process and the output of the second. Note that communication and information are not synonymous terms. The formal incorporation of information and process into a definition of communication provides a model of communication that captures much of the common sense meaning of communication while allowing us to both accurately predict and precisely explain a great deal about communication systems. Dervin [Der93], in discussing the discipline of communication, notes that ``It is process, however--the verbs of communicating--where we have something to offer that is, if not ultimately unique, at least for now ahead of the others."
How do we study ``what happens in the elusive moments of human communicatings" [Der93], and what are ``communicatings"? When communication is defined in terms of informative processes, one can study both the information that is conveyed and the processes that carry it. Definitions of communication often involve terms such as knowledge, belief, meaning, or intention. Moving beyond terminology about which many epistemologists and cognitive psychologists disagree to a definition that is often consistent with these abstract ideas but is based on more precise concepts enables us to use and build on the definition, as well as measure the output of communicating phenomena, both human and non-human. Human communication, a subset of all communication, plays a special role in the study of communication, but human communication is not equivalent to communication, and the former needs to studied as a subset of the latter. A precise but general definition of communication based on information requires a precise and discipline independent definition of information [Los97]. This will be provided below.
The study of communication phenomena may be divided into the experimental and the theoretical. Experimental studies of communication phenomena examine how informative processes work and precisely what information is provided by them. Statements are particular to a specific situation or domain and generalizability often becomes problematic. Theoretical studies of communication, on the other hand, address on a more abstract level the nature of processes and their outputs, as well as the inter-relationships between processes and their inputs and outputs. Mentioning inputs and outputs brings to mind introductory computer classes where this terminology is often introduced. Theoretical communication studies often use terminology similar to that used in computer science, with both disciplines borrowing terminology from the interdisciplinary theory developing in an area intersecting mathematics, computer science, communications, and engineering. Process and information are based on concepts in this intersection of disciplines.
Why should one be interested in a precise definition of communication? Having a useful definition or model of a phenomenon allows one to describe observations in a consistent way. In addition, such a model may allow us to accurately predict the characteristics of previously unseen communication systems. Most importantly, a successful definition and model helps us to explain how the system operates, leading one to an understanding of the nature of the system.
A satisfactory definition of communication should preserve some of the ideas in the common understanding of the term. Such a definition should be consistent and include only those items that need to be included, omiting mention of aspects that need not be included. At the same time, a definition should allows us to both better understand what communication is, defining clearly what phenomena are to be included and which are to be excluded from the domain of communicative phenomena, as well as to measure and evaluate communication systems both quantitatively and qualitatively. Qualitative studies emphasize understanding in a way that demands precision, and we believe that this definition brings to the discipline of communication a precision that is necessary and sufficient for both qualitative and quantitative studies. The increased understanding gained from a precise definition comes from statements of what is and what isn't communication, as well as how a communicative system functions. Being able to describe how communication takes place allows one to manipulate system components, improving the quantity or quality of communication taking place. A precise statement of the function of a system also leads to improved evaluative methods, with feedback from these leading to improved systems, and so forth. A clear statement of the domain of study allows one to focus on a phenomenon that is definitely part of communication, and thus worthy of study in depth, or one may address other phenomena with the understanding that they are clearly less central to the field.