Rhetorics and visualisation
Claire Dorman's introduction to the use of rhetorical figures in multimedia design is primarily based on experiences from production of web-pages.

Parts of Rhetoric

"Humans are symbol-making creatures. We communicate by symbols -- growls and grunts, hand signals and drawings painted on cave walls in prehistoric times. Later we developed languages, associating sounds with ideas. Eventually Homo Sapiens developed writing, perhaps first symbols scratched on rocks, then written more permanently on tablets, papyrus, and paper. Today we transmit symbols -- coded digital signals of voice, graphics, video and data -- around the world at close to the speed of light."
Bell Labs Celebrates 50 years of Information Theory.

Communication and Theory

Communications were the defining paradigm of the 20th century and seem certain to remain central to society in the 21st. Part of the reason for its importance is because communications refers to every kind of meaningful interchange between lifeforms. Communication of information has come to be the metaphor which permeates our understanding of life itself.

More prosaically, if one is in the business of communicating it is worth understanding the mechanisms which structure communications from the biggest networks to the individual and cellular level.

The word 'communication derives from the Latin verb communicare, -- "to talk together, confer, discourse, and consult, one with another". It is also intimately related to the Latin communitas, meaning not only community but also fellowship and justice in human dealings.

Human beings are defined by their ability to communicate in a huge variety of ways. Important understandings of the nature of communication have come from many disciplines including anthropology, electrical and computer science, psychology, linguistics, cellular biology, neurology, etc. etc.

Rhetoric

One of the earliest theories of communications is called 'Rhetorics' which analysed and systemised the production and delivery of speech acts. For the Ancient Greeks, public speaking was the highest form of communication and every male of the ruling classes could expect to have to give numerous public addresses over his lifetime. Education was also based on verbal presentation and dialogue exemplified by Aristotle's 'Discourses'. The Ancient Greeks' system of Rhetoric was based on centuries of oral culture and still shapes the methods by which westerns produce and analyse human communication. Many of the rhetorical figures defined by rhetorics remain central to our understandings of how communication functions.

metaphor n. [G. meta, change; phor, form] 1. The main logic of art, as opposed to normative or rational causality, where change of form is disallowed. 2. Metaphor is the ability of one thing or idea to signify, in addition to itself, another thing or idea; metaphor implies levels of meaning, often opposed, operating within a single idea or work. 3. Commonly divided into four subspecies: (1) metaphor proper, the perception of the world as a set of signs; (2) metonymy, the use of a part of a whole or pair, such as smoke for fire, head for person, crown for king, king for nation; (3) synecdoche, the form of metonymy where the part stands for, or becomes, the whole, which might be taken to be the global condition of all art; (4) irony, the use of one thing to indicate its opposite, e.g. falsehood for truth

The Random House Dictionary gives the following definitions of "rhetoric": .... the ability to use language effectively...the art or science of all specialized literary uses of language in prose or verse, including the figures of speech...the undue use of exaggeration or display; bombast....(formerly) the study of the composition and delivery of persuasive speeches; the art of oratory...(in classical oratory) the art of influencing the thought and conduct of one's hearers...(1229) In its Greek roots, rhetoric is related to techne: from this we can appreciate its sense as technique, as technology of persuasion--"the art of influencing the thought and conduct of one's hearers." The original association with the oral tradition has been extended to the medium of print, and with it has followed our intuition that writing has much to do with voice, and other auditory features such as rhythm and verbal music. We often know that we are included in a community of discourse as much by the sound of the language as by its sense.

Rhetoric focuses on communication in a context. Speech or writing never occurs in a vacuum, but in some historical, cultural, temporal setting that is intimately tied up with how one frames discourse. In one sense, the "rhetorical situation" refers to what prods or inspires communication: a pressing need, a conventional ceremony, a specific intention. The Greeks spoke in terms of kairos, a term that means something like "generative timeliness," or "occasion." Thus, a given kairos calls forth certain kinds of things to say. The Romans spoke of "decorum," a significant, overarching principle of rhetoric, meaning appropriateness of discourse: one needed to fit one's words not only to the subject matter, but to the audience in a given place at a given time. Sensibility to the kairos enabled one to have decorum in choosing to say the right thing to one's audience in the right way. Because the rhetorical situation has so much to do with the nature of those who listen to or read discourse, audience itself becomes a principle term in understanding rhetoric. Rhetoric is never about discourse in the abstract; it is always concerned with directing one's words with specific intentions towards specific audiences.

MAIN CONCEPTS

• information = unpredictability
• channel
• entropy
• noise
• redundancy

Entropy as defined by Clausius is not just something that happens to steam engines or to glasses of water. It is a universal tendency that is as true for the energy transactions of the stars in the sky as it is for the tea kettle on the stove. Because the universe is presumed to be a closed system, and since Clausius demonstrated that the entropy of such systems tends to increase with the passage of time, the gloomy prediction of a distant but inevitable "heat death of the universe" was a disturbing implication of the second law of thermodynamics.

Entropy in Information and Coding Theory

Further information about entropy

Information Theory

When a new communication system comes along, you might read, for example, that it is "capable of carrying 90,000 volumes of an encyclopedia per second." 90,000 volumes is a characterization of 3.2 trillion bits, which is even harder to picture than all those books. Bits, especially in the now common phrase "bits per second," are a legacy of Claude Shannon. The pioneer of information theory, Shannon developed a theory of how much information can be sent per unit of time in a system with a given, limited amount of transmission power. Shannon inspired an explosion of creative ways for compressing bits (extracting only the "real" information), encoding them for sending over a channel, and interpreting them later or elsewhere with any desired level of accuracy.
Information Theory

In the late 1940s Claude Shannon, a research mathematician at Bell Telephone Laboratories commissioned to design more efficient telephone lines, invented a mathematical theory of communication which quickly became known as Information Theory.

Information Theory regards information as only those symbols that are uncertain to the receiver.

For example, people used to send telegraph messages leaving out nonessential words such as "a" and "the." In the same vein, predictable symbols can be left out, as in the sentence, "only infrmatn esentil to understandn mst b tranmitd."

Shannon made it clear that uncertainty is the very commodity of communication.

It is important to note that 'information' as understood in information theory has nothing to do with any inherent meaning in a message. It is rather a degree of order, or nonrandomness, that can be measured and treated mathematically much as mass or energy or other physical quantities are.

The amount of information, or uncertainty, output by an information source is a measure of its entropy. In turn, a source's entropy determines the amount of bits per symbol required to encode the source's information.

His ground-breaking approach introduced a simple abstraction of human communication, called a channel. Every channel has a fixed upper limit on the information it can carry.

As originally conceived, the model contained five elements

• an information source,
• a transmitter,
• a channel of transmission,
• a receiver,
• and a destination

all arranged in linear order. Messages (electronic messages, initially) were supposed to travel along this path, to be changed into electric energy by the transmitter, and to be reconstituted into intelligible language by the receiver.

In 1952, four years after he published his groundbreaking theory, Shannon invented an electrical mouse with a telephone relay switch brain. Its ability to find its way through a maze demonstrated that computers could learn, a startling revelation to those who, until then, had used them only as giant adding machines.

In 1956, at the age of forty, Shannon was one of the organizers of the conference at Dartmouth that gave birth to the field of artificial intelligence. From the prewar discoveries that scooped Wiener and von Neumann, to the explorations in the 1950s that led to both AI and multi-access computer systems, his life and ideas formed the single most important bridge between the wartime origins of cybernetics and digital computers and the present age of artificial intelligence and personal computing.

Tools for Thought
Howard Rheingold

In order to quantitatively analyze transmission through the channel he also introduced a measure of the amount of information in a message.

To Shannon, the measure of the amount of information is its unpredictability, 'a measure of surprise'. For Shannon a message is very informative if the chance of its occurrence is small. If, in contrast, a message is very predictable, then it has a small amount of information -- one is not surprised to receive it. The less predictable the message, the more information it carries. The more information, the greater its effect in combating entropy.

To complete his quantitative analysis of the communication channel, Shannon introduced

• the entropy rate,
• a quantity that measured a source's information production rate
• a measure of the information carrying capacity, called the communication channel capacity.

He showed that if the entropy rate, the amount of information you wish to transmit, exceeds the channel capacity, then there were unavoidable and uncorrectable errors in the transmission. This is intuitive enough. What was truly surprising, though, is that he also showed that if the sender's entropy rate is below the channel capacity, then there is a way to encode the information so that it can be received without errors. This is true even if the channel distorts the message during transmission.

One of the most important feature of Shannon's theory was the concept of entropy, which he demonstrated to be equivalent to a shortage in the information content in a message. According to the second law of thermodynamics, entropy (the degree of randomness in any system), always increased. Thus many sentences could be significantly shortened without losing their meaning. Shannon proved that in a noisy conversation, signal could always be sent without distortion. If the message is encoded in such a way that it is self-checking, signals will be received with the same accuracy as if there were no interference on the line. A language, for example, has a built in error-correcting code. Therefore, a noisy party conversation is only partly clear because half the language is redundant. Shannon's method were soon seen to have applications not only to computer design but to virtually every subject in which language was important such as linguistic, psychology, cryptography and phonetics.

Noise vs. Information

Noise is the enemy of information. For Shannon noise is more than an irritating sound or static on the line. It is anything added to the signal that's not intended by the source. Usually that kind of interference is an unintended by-product of the situation. In nonelectrical channels, noise can be smudged newsprint, 'ah-um-er' vocal filler, or visual movement that distracts the listener.

Noise may be intentional. For example, hecklers try to drown out the words of a speaker in order to prevent the audience from considering an opposing viewpoint. We can even generate white noise to mask more disruptive sounds. But whether accidental or planned, noise cuts the information-carrying capacity of the channel between the transmitter and receiver.

Shannon describes the relationship with a simple equation:

Channel Capacity = Information + Noise

The way to offset noise is through increased redundancy. Without a great amount of repetition, reiteration, and restatement, a noisy channel is quickly overloaded. Yet too much redundancy is inefficient. Needless duplication diminishes our chance to make novel statements, and our initially avid audience may become bored and inattentive.

Shannon adapted Information Theory to analyze ordinary human language. He analyzed a huge number of communications, from code transmissions to telephone conversations to James Joyce novels, in order to understand the relationship between:

1. the message intended for transmission and
2. the redundant information tacked on to ensure that the message is understood correctly.

He showed that language is extremely redundant, using more symbols and words than necessary to convey messages. Redundancy is crucial for clear communication in a 'noisy' environment, but when noise is low the redundancy can be stripped out and the message highly compressed. In this connection, Shannon examined the frequency of word correlations in the English language. Pairs of words which often appear together (for instance, 'gutless' and 'wonder') show a higher degree of redundancy than less common pairs (perhaps 'elegant' and 'monsoon'). Shannon showed that a randomly generated string of words could sound remarkably like meaningful English, so long as each word had a high correlation with the word before it. The resemblance to English is even greater if the nonsense string is generated using word triplets, rather than word pairs.

Redundancy is the greatest antidote to entropy. Most written and spoken languages, for example, are roughly half-redundant. If 50 percent of the words on this screen were taken away at random, what remained would still be intelligible. Similarly, if only half of radio news commentator's words are heard, the broadcast can usually still be understood. Redundancy is apparently involved in most human activities, and, because it helps to overcome the various forms of entropy that tend to turn intelligible messages into unintelligible ones (including psychological entropy on the part of the receiver), it is an indispensable element for effective communication.

Criticism and achievements

Information Theory made it possible to determine the theoretical limit of any channel's information-carrying capacity. Using Information Theory as a mathematical benchmark, engineers were finally able to provide efficient, error-free transmission over noisy channels. IT also made possible the development of digital systems, which handle information -- voice, data video -- in streams of coded pulses. Whilst Shannon's ideas have been soundly criticised for their abstraction from the realities of most human communication, Information theory is useful for understanding entities such as print publishing which are more nearly one-way communication channels.

"...To live effectively is live with adequate information..."

Weiner

Cybernetics is all about servo-mechanisms, goal-seeking behavior, feedback loops, positive and negative feedback systems, self-stabilising systems, homeostasis and the control of systems, and how they might apply to biological or mechanical systems.
Software for the Brain

Wiener: Ideas

"We need new tools with which to approach organized complexity, interdependence, and regulation. These tools emerged in the United States in the 1940s from the cross-fertilisation of ideas that is common in the melting pot of the large universities... In the forties the first step forward led from the machine to the living organism, transferring from one to the other the ideas of feedback and finality and opening the way for automation and computers."
History of Cybernetics and Systems Science

Cybernetics

Shannon's model is deficient in that it represents communication as a one-way flow of information. It fails to take into account the fact that most communicative acts involve a simultaneous flow of information in both directions. Cybernetics addressed the reciprocal nature of communication.

Every interaction involves a feedback loop -- I speak to you, you respond to (or ignore) me, I react and so on. We are acculturated to notice the reactions from our conversation partners and we adjust our interactions accordingly, even if irrationally. Have you ever lost your voice and been reduced to whispering, only to discover that everyone whispers back to you? People with severe communication impairment (SCI), especially people with impaired facial expression, may never be able to give standard feedback, and all their interactions may be skewed as a result. If someone doesn't respond when we speak, we repeat what we said more loudly.
IT TAKES TWO TO TANGO: THE IMPORTANCE OF FEEDBACK IN COMMUNICATION Rosemary Crossley

Norbert Weiner was one of the originators of cybernetic theory and originator of the word 'cybernetics', based the word on the Creek 'kubemetes' meaning literally 'steersman'. Working independently through the Bell Lab program, Wiener conceived of human attempts to control entropy through feedback as exactly parallel to what happens in communication machines.

It was Weiner's strongest contention that: "society can only be understood through a study to the messages and communication facilities which belong to it".

A child prodigy, he entered university at 11, studied at Harvard, Cornell, Cambridge, and G?ttingen universities, and became professor of mathematics at the Massachusetts Institute of Technology (1932-1960). During World War II he worked on guided missiles, and his study of the handling of information by electronic devices, using the feedback principle, encouraged comparison between these and human mental processes in Cybernetics (1948) and other works.

Feedback is a way to introduce learning into the system, something ignored by Shannon and Information Theory.

The Genesis of Cybernetics

In 1940 Wiener worked with a young engineer, Julian H. Bigelow, to develop automatic range finders for antiaircraft guns. Such servomechanisms are able to predict the trajectory of an airplane by taking into account the elements of past trajectories. During the course of their work Wiener and Bigelow were struck by two astonishing facts: the seemingly 'intelligent' behavior of these machines and the 'diseases' that could affect them. The range-finders' behavior appeared to be 'intelligent' because they dealt with 'experience' (the recording of past events) and predictions of the future. There was also a strange defect in performance: if one tried to reduce the friction, the system entered into a series of uncontrollable oscillations.

Impressed by this disease of the machine, Wiener asked Rosenblueth whether such behavior was found in man. The response was affirmative: in the event of certain injuries to the cerebellum, the patient cannot lift a glass of water to his mouth; the movements are amplified until the contents of the glass spill on the ground. From this Wiener inferred that in order to control a finalized action (an action with a purpose) the circulation of information needed for control must form "a closed loop allowing the evaluation of the effects of one's actions and the adaptation of future conduct based on past performances." This is typical of the guidance system of the antiaircraft gun, and it is equally characteristic of the nervous system when it orders the muscles to make a movement whose effects are then detected by the senses and fed back to the brain.

Thus Wiener and Bigelow discovered the closed loop of information necessary to correct any action -- the negative feedback loop -- and they generalised this discovery in terms of the human organism.

Feedback

A bureaucracy and a factory are automated machines in Wiener's view. The whole world -- even the universe -- could be seen as one big feedback system subject to the relentless advance of entropy, which subverts the exchange of messages that is essential to continued existence (Wiener, 1954).

This concept of interdependent communications systems was coupled with Wiener's assertion that a machine that changes its responses based on feedback is a machine that learns.

The original foundation of cybernetics was limited to the observation of the states of a system, with the drawback being that the states observed -- and defined -- were wholly dependent on an observer who was construed as impartial and having no effect on the observed system. "New" or "second order" cybernetics includes the observer as a participant in and part of the observed system; the focus has shifted from communication and control to interaction (Pask, 1992).

Characteristics of cybernetic systems

• Complexity: Cybernetic systems are complex structures, with many heterogeneous interacting components.
• Mutuality: These many components interact in parallel, cooperatively, and in real time, creating multiple simultaneous interactions among subsystems.
• Complementarity: These many simultaneous modes of interaction lead to subsystems which participate in multiple processes and structures, yielding any single dimension of description incomplete, and requiring multiple complementary, irreducible levels of analysis.
• Evolvability: Cybernetic systems tend to evolve and grow in an opportunistic manner, rather than be designed and planned in an optimal manner.
• Constructivity: Cybernetic systems are constructive, in that as they tend to increase in size and complexity, they become historically bound to previous states while simultaneously developing new traits.
• Reflexivity: Cybernetic systems are rich in internal and external feedback, both positive and negative. Ultimately, they can enter into the "ultimate" feedback of reflexive self-application, in which their components are operated on simultaneously from complementary perspectives, for example as entities and processes. Such situations may result in the reflexive phenomena of self-reference, self-modeling, self-production, and self-reproduction.
  History of Cybernetics and Systems Science

Cybernetics have found applications far beyond the obvious ones of robotic systems and machines. Stan Beer, for example, analyzed business structures using the cybernetic model in his 19? book, The Brain of the Firm. The Internet is itself the epitome of a cybernetic system.

Semiotics is the general study of signs or of whatever conveys meaning.

Semiotics attempts to articulate a comprehensive theory of signs.

Key figures in the early development of semiotics were the American philosopher Charles Sanders Peirce and later Charles William Morris, who developed a behaviorist semiotics. Leading modern semiotic theorists include Roland Barthes, Algirdas Greimas, Yuri Lotman, Christian Metz, Umberto Eco and Julia Kristeva.

It is difficult to disentangle European semiotics from structuralism in its origins; major structuralists include not only Saussure but also Claude Levi-Strauss in anthropology (who saw his subject as a branch of semiotics) and Jacques Lacan in psychoanalysis.

Structuralism is an analytical method which has been employed by many semioticians and which is based on Saussure's linguistic model. Structuralists seek to describe the overall organization of sign systems as 'languages' - as with Levi-Strauss and myth, kinship rules and totemism, Lacan and the unconscious and Barthes and Greimas and the 'grammar' of narrative. They engage in a search for 'deep structures' underlying the 'surface features' of phenomena.

However, contemporary social semiotics has moved beyond the structuralist concern with the internal relations of parts within a self-contained system, seeking to explore the use of signs in specific social situations. Modern semiotic theory is also sometimes allied with a Marxist approach which stresses the role of ideology.
Semiotics for Beginners Daniel Chandler.

see also Heisenberg Principle

see Semiotics - Icons, indexes, symbols for discussion of their specific meanings in semiotics

D.I.Y. Semiotic Analysis
and
Glossary of Key Terms

Semiotics for Beginners Daniel Chandler:

The semiotics of visual communication
S¿ren Kolstrup

THE SEMIOTICS OF MULTIMEDIA - an introduction to multimedia production: Great teaching papers covering a wide range of multimedia production and reception issues

Abduction and A Theory of Visual Interpretation, Sandra E. Moriarty, Communication Theory, 6:2 (May 1996),
The focus of this essay is on how viewers understand a visual and interpret its meaning. The central focus of this discussion is interpretation--how meaning is arrived at--and this paper makes the argument that Peirce's notion of abductive reasoning provides a useful theoretical frame in which to analyze visual interpretation. It is the thesis of this paper that a different kind of interpretive logic operates for visual communication processes than for language-based communication processes and this logic is best articulated in the semiotic literature where the concept of interpretation is more carefully conceptualized.

Visuals - perceptual aspects, Bj¿rn Laursen

A Conceptual Map of Visual Communication, Journal of Visual Literacy, 17:2 (1997).

Semiotics

Semiotics, a term taken from the work of American philosopher Charles S. Peirce, deals with communication as the science of signs and meanings, and their production and exchange.

Signs are all the ways that we communicate meaning in society, not just language.

Critical analysis from a semiotic perspective concerns itself with the role of texts in our culture. It should be noted that a 'text' can exist in any medium and may be verbal, non-verbal, or both. Semiotically, a text is an assemblage of signs (such as words, images, sounds and/or gestures) constructed (and interpreted) with reference to the conventions associated with a genre and in a particular medium of communication.

It is this cultural perspective, combined with linguistic analysis pioneered by Ferdinand de Saussure and subsequently developed by followers such as Roland Barthes, that makes this branch of communication theory so useful.

Because semioticians believe that cultural behavior can be systematically analyzed, analysis can be focused on such codes of dress, music, advertising, and other forms of communication.

"Semiotics is a form of structuralism, for it argues that that we cannot know the world on its own terms, but only through the conceptual and linguistic structures of our culture. Empiricism argues exactly the opposite. For the empiricist the work of the researcher is to discover the meanings and patterns that already exist in the world" (Fiske, 1990, p. 115).

Saussure founded semiology by offering it as 'a science that studies the life of signs within society'. Saussure saw language as being an ordered system of signs whose meanings are arrived at arbitrarily by a cultural convention. He contended that society is made up of a multiplicity of language-like 'codes', in all media (speech, literature, architecture, clothes, vehicles, cooking, and so on), which establish objects such as texts, buildings, cars and so forth as 'signs' having cultural meaning over and above their constructions and functions. This is of course, something that artists, writers and social observers have always known -- everything in society is telling us something.

...'reality' is always encoded, or rather the only way we can perceive and make sense of reality is by the codes of our culture. There may be an objective, empiricist reality out there, but there is no universal, objective way of perceiving and making sense of it. What passes for reality in any culture is the product of the culture's codes, so 'reality' is always already encoded, it is never 'raw'. Fiske (1987 pp 4-5)

Major concepts in semiotics

sign

Anything can be a sign as long as someone interprets it as 'signifying' something - referring to or standing for something other than itself. We interpret things as signs largely unconsciously by relating them to familiar systems of conventions. It is this meaningful use of signs which is at the heart of the concerns of semiotics.

A sign has two parts: the signifier and the signified

• a 'signifier' - the form which the sign takes
• the 'signified' - the concept it represents

The sign is the whole that results from the association of the signifier with the signified. The relationship between the signifier and the signified is referred to as 'signification.' The relationship between the signifier and the signified is arbitrary in so far as any 'thing' can refer to any other thing or concept as long as enough people agree that it does.

code

The concept of the 'code' is fundamental in semiotics. Production and interpretation of texts depends upon the existence of codes or conventions for communication. Since the meaning of a sign depends on the code within which it is situated, codes provide a framework within which signs make sense. Indeed, we cannot grant something the status of a sign if it does not function within a code.

Any act of 'reading' requires a code. There are obvious codes such as the alphabet or the socially-accepted meanings for utterances, but there are also the less obvious codes such as dress and speech patterns.

Even an indexical and iconic sign such as a photograph involves a translation from three dimensions into two, and training in 'a new way of seeing'. What human beings see does not resemble a sequence of rectangular frames, and camerawork and editing conventions are not direct replications of the way in which we see the everyday world. When we look at things around us in everyday life we gain a sense of depth from our binocular vision, by rotating our head or by moving in relation to what we are looking at. To get a clearer view we can adjust the focus of our eyes. But for making sense of depth when we look at a photograph none of this helps. We have to decode the cues.

Some theorists argue that even our perception of the everyday world around us involves codes. 'Perception depends on coding the world into iconic signs that can re-present it within our mind. The force of the apparent identity is enormous, however. We think that it is the world itself we see in our "mind's eye", rather than a coded picture of it' (Nichols 1981, 11-12).

According to the Gestalt psychologists - notably Max Wertheimer (1880-1943), Wolfgang K?hler (1887-1967) and Kurt Koffka (1886-1941) - there are certain universal features in human visual perception which in semiotic terms can be seen as constituting a perceptual code.

Social codes

[In a broader sense all semiotic codes are 'social codes']

• verbal language (phonological, syntactical, lexical, prosodic and paralinguistic subcodes)
• bodily codes (bodily contact, proximity, physical orientation, appearance, facial expression, gaze, head nods, gestures and posture)
• commodity codes (fashions, clothing, cars)
• behavioral codes (protocols, rituals, role-playing, games).

Textual codes

[Representational codes]

• scientific codes, including mathematics;
• aesthetic codes within the various expressive arts (poetry, drama, painting, sculpture, music, etc.) - including classicism, romanticism, realism
• genre, rhetorical and stylistic codes: narrative (plot, character, action, dialogue, setting, etc.), exposition, argument and so on
• mass media codes including photographic, televisual, filmic, radio, newspaper and magazine codes, both technical and conventional (including format).

Interpretative codes

[There is less agreement about these as semiotic codes]

• perceptual codes: e.g. of visual perception (note that this code does not assume intentional communication)
• ideological codes: More broadly, these include codes for 'encoding' and 'decoding' texts - dominant (or 'hegemonic'), negotiated or oppositional . More specifically, we may list the 'isms', such as individualism, liberalism, feminism, racism, materialism, capitalism, progressivism, conservatism, socialism, objectivism, consumerism and populism; (note, however, that all codes can be seen as ideological).

These three types of codes correspond broadly to three key kinds of knowledge required by interpreters of a text, namely knowledge of:

• 1. the world (social knowledge);
• 2. the medium and the genre (textual knowledge);
• 3. the relationship between (1) and (2) (modality judgments)

Other on-line references

Richard Barbrook, Media Freedom: the contradictions of communications

Signals, signs, and symbols, three related components of communication processes found in all known cultures, have attracted considerable scholarly attention because they do not relate primarily to the usual conception of words or language.

Each is apparently an increasingly more complex modification of the former, and each was probably developed in the depths of prehistory before, or at the start of, man's early experiments with vocal language.

Easterby, R. S. (1970). 'The perception of symbols for machine displays' Ergonomics, 13(1), 149-158 quoted in Boling, Elizabeth. 'Components of Perceptibility in Symbol Signs' 1996

Types of communication

Nonvocal communication

Signals

A signal may be considered as an interruption in a field of constant energy transfer. An example is the dots and dashes that open and close the electromagnetic field of a telegraph circuit. Such interruptions do not require the construction of a man-made field; interruptions in nature (e.g., the tapping of a pencil in a silent room, or puffs of smoke rising from a mountain top) may produce the same result. The basic function of such signals is to provide the change of a single environmental factor in order to attract attention and to transfer meaning. A code system that refers interruptions to some form of meaningful language may easily be developed with a crude vocabulary of dots, dashes, or other elemental audio and visual articulations. Taken by themselves, the interruptions have a potential breadth of meaning that seems extremely small; they may indicate the presence of an individual in a room, her impatience, agreement, or disagreement with some aspect of her environment or, in the case of a scream for help, a critical situation demanding attention. Coded to refer to spoken or written language, their potential to communicate language is extremely great.

Signs

Signs contain greater amounts of meaning of and by themselves than signals Ashley Montagu, an anthropologist, has defined a sign as a "concrete denoter" possessing an inherent specific meaning, roughly analogous to the sentence "This is it; do something about it!"

The most common signs encountered in daily life are pictures or drawings, although a human posture like a clenched fist, an outstretched arm, or a hand posed in a "Stop" gesture may also serve as signs. The main difference between a sign and a signal is that a sign (like a policeman's badge) contains meanings of an intrinsic nature; a signal (like a scream for help) is merely a device by which one is able to formulate extrinsic meanings.

All known cultures utilise signs to convey relatively simple messages swiftly and conveniently. Signs may depend for their meaning upon their form, setting, colour, or location. Taken en masse, any society's lexicon of signs makes up a rich vocabulary of colourful communications.

Symbols

Symbols are more difficult than signs to understand and to define because, unlike signs and signals, they are intricately woven into an individual's ongoing perceptions of the world. They appear to contain a dimly understood capacity that (as one of their functions), in fact, defines the very reality of that world.

The symbol has been defined as any device with which an abstraction can be made. Although far from being a precise construction, it leads in a profitable direction. The abstractions of the values that people imbue in other people and in things they own and use lie at the heart of symbolism. Here is a process, according to the British philosopher Alfred North Whitehead, whereby some components of [the mind's] experience elicit consciousness, beliefs, emotions, and usages respecting other components of experience. In Whitehead's opinion, symbols are analogues or metaphors (that may include written and spoken language as well as visual objects) standing for some quality of reality that is enhanced in importance or value by the process of symbolization itself.

Almost every society has evolved a symbol system whereby, at first glance, strange objects and odd types of behavior appear to the outside observer to have irrational meanings and seem to evoke odd, unwarranted cognitions and emotions. Upon examination each symbol system reflects a specific cultural logic, and every symbol functions to communicate information between members of the culture in much the same way as, but in a more subtle manner than, conventional language.

Although a symbol may take the form of as discrete an object as a wedding ring or a totem pole, symbols tend to appear in clusters and depend upon one another for their accretion of meaning and value. They are not a language of and by themselves; rather they are devices by which ideas too difficult, dangerous, or inconvenient to articulate in common language are transmitted between people who have acculturated in common ways. It does not appear possible to compile discrete vocabularies of symbols, because they lack the precision and regularities present in natural language that are necessary for explicit definitions.

Easterby (1970) described symbol signs as having five basic components:

• pragmatic, the context in which the symbol will be used;
  The pragmatic component is a symbol's context. The viewer's ability to perceive the function of a button accurately is affected by the context in which the button is encountered. A symbol's context may have multiple components.
• semantic, the symbol's relationship to its referent;
  The semantic component is a symbol's relationship to its referent. This relationship may be concrete, as is the case when the image of a pencil is used to indicate the pencil tool in an electric palette. The relationship may also be abstract, as is the case when a red circle is used to mean "stop."
• syntactic, the symbol's relationship to others in the set;
  The syntactic component is the symbol's relationship to the entire symbol set of which it is a part. The location of the symbols in relation to each other is part of the syntactic component for any one symbol in the set.
• visibility, how well the symbol can be seen;
  The visibility component refers to whether the symbol may be seen at all, and with what degree of clarity. Although visbility would seem to be the easiest component to acheive effectively, it can suffer when a symbol is moved from a color display to gray-scale or black and white, or when the viewer suffers from color-blindess or lack of visual acuity.
• discriminability, how well the symbol is differentiated from others;
  The discriminability component describes how easily a symbol may be differentiated from the others in a set. Symbols differing from each other only in detail may not be sufficiently differentiated for the viewer to reliably identify the one she wants.

Icons

Gestures

Professional actors and dancers have known since antiquity that body gestures may also generate a vocabulary of communication more or less unique to each culture. For example, Fran?ois Delsarte, a 19th-century French teacher of pantomime and gymnastics, described the ingenious and complex language of contemporary face and body positions for theatrical purposes.

Proxemics

Of more general, cross-cultural significance are the theories involved in the study of "proxemics" developed by a U.S. anthropologist, Edward Hall. Proxemics involves the ways in which people in various cultures utilize both time and space as well as body positions and other factors for purposes of communication. Hall's 'silent language' of nonverbal communications consists of such culturally determined interactions as the physical distance or closeness maintained between individuals, the body heat they give off, odours they perceive in social situations, angles of vision they maintain while talking, the pace of their behavior, and the sense of time appropriate for communicating under differing conditions.

By comparing matters like these in the behavior of different social classes (and in varying relationships), Hall elaborated and codified a number of sophisticated general principles that demonstrate how certain kinds of nonverbal communication occur. Although Hall's most impressive arguments are almost entirely empirical, and many of them are open to question, the study of proxemics does succeed in calling attention to major features of communication dynamics rarely considered by linguists and symbologists. Students of words have been more interested in objective formal vocabularies than in the more subtle means of discourse unknowingly acquired by the members of a culture.

Note that Semiotics uses different definitions for some of these terms.

Mass and public communication

Prerequisites for mass communication

Whilst it is tempting to look only at the history of technological development and trace the necessary pre-technologies which led to the development of our diverse forms of public and mass communication, this is is only a small part of the story. For example, large literate population was necessary before giant publishing and newspaper empires might employ extant communications technology to satisfy widespread desires or needs for popular reading materials.

Affluence and interest were (and are) prerequisites for the maintenance of the radio, television, cinema, and recording industries, institutions that are presently most highly developed in wealthy, industrial nations. Even in countries in which public communication is employed largely for government propaganda, certain minimal economic and educational standards must be achieved before this persuasion is accepted by the general public.