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" (orator). 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 (or thing) 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 Epistemology in Communication Theory Communication theories vary substantially in their epistemology, and articulating this philosophical commitment is part of the theorizing process. Although the various epistemic positions used in communication theories can vary, one categorization scheme distinguishes among interpretive empirical, metric empirical or post-positivist, rhetorical, and critical epistemologies. Communication theories may also fall within or vary by distinct domains of interest, including information theory, rhetoric and speech, interpersonal communication, organizational communication, sociocultural communication, political communication, computer-mediated communication, and critical perspectives on media and communication. Interpretive Empirical Epistemology Interpretive empirical epistemology or interpretivism seeks to develop subjective insight and understanding of communication phenomena through the grounded study of local interactions. When developing or applying an interpretivist theory, the researcher themself is a vital instrument. Theories characteristic of this epistemology include structuration and symbolic interactionism, and frequently associated methods include discourse analysis and ethnography. Metric Empirical or Post-Positivist Epistemology A metric empirical or post-positivist epistemology takes an axiomatic and sometimes causal view of phenomena, developing evidence about association or making predictions, and using methods oriented to measurement of communication phenomena. Post-positivist theories are generally evaluated by their accuracy, consistency, fruitfulness, and parsimoniousness. Theories characteristic of a post-positivist epistemology may originate from a wide range of perspectives, including pragmatist, behaviorist, cognitivist, structuralist, or functionalist. Although post-positivist work may be qualitative or quantitative, statistical analysis is a common form of evidence and scholars taking this approach often seek to develop results that can be reproduced by others. Rhetorical Epistemology A rhetorical epistemology lays out a formal, logical, and global view of phenomena with particular concern for persuasion through speech. A rhetorical epistemology often draws