1.3 Common Models of Communications Theory

While some constants of communication have prevailed over time, it wasn’t until the mid-20th century that scholars and scientists began to explore communications theory and develop models to shape the way we study communications.

Linear Model

One of the first to explore this field was Harold Lasswell, a political scientist, sociologist, and psychologist who developed a linear model of communication (1948).1 In this model, the exchange of information can be broken down into a strategic planning exercise, identifying the communicator, the concept (or idea) being communicated, the channel of communication, the intended receiver (or audience), and the desired effect of the communication. Lasswell’s model operates under the proposition of five questions:

1. Who is the communicator?

2. What is the basic concept or content that is being communicated?

3. Which channel is being used to transmit the communication?

4. To whom is the message communicated?

5. What effect is desired from the communication?

Answering these basic questions as a model for communication continues to be practiced and studied universally across all forms of communication, including interpersonal, group, and mass communication. While Lasswell developed the model to study mass communication, this linear model can be applied for practical use in fields such as journalism, multimedia, publishing, and corporate and governmental public relations.

For instance, if you were to plan a marketing campaign on behalf of dairy farmers, you would first identify an ad agency or spokesperson. Next, you would identify the benefits of dairy products, appealing to the key demographic’s desire for tasty things like cheese, ice cream, and milk itself. Then, you would decide what means of communication would be most effective. In this case, let’s suppose video commercials (for television and internet) would be your best bet. You would then identify your target audience through basic analytics. In this case, it would be any consumer who is part of the key demographic that shops for groceries. Your desired effect should be rather obvious in that you want people to buy more dairy products, which can be quantified through sales figures.

While the Lasswell model can be applied to any form of communication, there are nuanced differences in the means by which it can be applied. For example, if you are the owner of a news agency, the order of the questions you answer to arrive at the desired effect on your audience may differ in practice. For most media owners, the primary goal is to keep the audience’s attention as long as possible, the message itself varies, and the means of delivery can be limited.

Shannon-Weaver Model

The Shannon-Weaver model (1949) was developed as part of a study by Claude Shannon and Warren Weaver, two engineers for Bell Telephone Laboratories.2 The goal of their study was to ensure that telephone signals (processed as radio waves) worked efficiently through the cables. Using a mathematical formula, they developed a simple linear model containing four primary components: sender, message, channel, receiver. The sender is an agent that transmits messages. The message is a signal that relays information to the receiver. The channel is the medium or platform used to exchange messages. Finally, the receiver is the agent that consumes or accepts messages.

All four of these components represented technological elements, not human beings. For instance, the “sender” in this model is not a person speaking but the microphone embedded in the telephone that transfers voice vibrations. The “message” is the radio waves, and the “channel” component represents the telephone itself that processes the voice waves into radio waves. The “receiver” is also represented by the telephone that processes radio waves into audible content that a person hears through the speaker.

Unlike Lasswell’s model, the basic utility of this linear model was not to study human communications but to improve telephone technology. Shannon-Weaver also identified the influence of “noise” interference that occurs while communicating over the telephone, such as background sounds, radio interference, loss of signal, and so on.

Shannon and Weaver’s study also identified three basic challenges to effective communication, including the technical problem, the semantic problem, and the effectiveness problem. The technical problem identifies the limits of the technology to transmit information accurately. The semantic problem identifies the challenges of finding precise meaning, and the effectiveness problem explores the degree to which the message’s meaning affects behavior.

During the time of Shannon and Weaver’s study, telephone technology was limited to radio signals sent through copper wire from one place to another. Those limits included loss of signal over long distances, radio frequency (RF) interference, and the availability and affordability of phone lines in low-income and rural areas.

For example, imagine you are working in Los Angeles in the year 1950, trying to understand instructions over the telephone from a manager located in New York City. You may not be able to hear every word as the volume dips, crackling from RF interference. A confused operator may patch another call over the same circuit, or the connection may be lost somewhere between St. Louis and Denver. These technical challenges were very real to anyone who used telephones decades ago.

The technical, semantic, and effectiveness problems cited in Shannon and Weaver’s findings were more visceral than theoretical. The practical discoveries of the Shannon-Weaver model certainly helped Bell Laboratories improve its technology, and the physical elements of telephone communication played a role as a metaphor in shaping contemporary communications theory.

Some have criticized this linear model as simplistic because it disregards other influences in communication, such as semiotics, power structures, and culture. The Shannon-Weaver model is particularly limited to elements of audio communication, leaving plenty of room to study other human factors involved in sharing information.

Sender-Message-Channel-Receiver Model

David Berlo expanded on the Shannon-Weaver model by introducing his own sender-message-channel-receiver (SMCR) model of communication in 1960.3 Berlo’s contribution listed other key subcomponents of each communication element, adding human context to the simplistic processes based on technology.

The SMCR model is unique for introducing individuals as the main components of communication. It regards the human communication process as more than a simple association with technology or physical interaction between elements such as microphones, wires, speakers, eyes, eardrums, and the skin’s touch. Berlo separates the communication process to account for the situational existence of the communicator and receiver (see the “sender” and “receiver” components in the figure above). The SMCR model also accounts for variables within the message itself and the means by which the message is received, beyond the auditory sense.

Berlo’s contribution to communications study, while limited as an interpersonal communications model, is notable for including a wide range of human variables, such as the communication skills, attitude, knowledge, social system, and culture of the sender and receiver. Some of these human elements can appear on a wide-ranging spectrum and are also subject to even wider semantic interpretation. For instance, the word “attitude” can mean any number of things to different people, especially when applied to communication. An example of this is someone who disregards a professor’s lecture because “I didn’t like her attitude,” whereas another person might use “attitude” to describe someone’s posture and body language. To consider Berlo’s model as an absolute real-world application for successful communication seems to depend on a lot of uncontrollable things falling into place, leaving us to consider if there can be any environment where two individuals can connect and share information.

Circular Model

Prior to Berlo’s model, Wilbur Schramm (1954) developed a circular model that uses many of the same elements of the linear approaches.4 Schramm’s model suggests that communication involves more than a simple transaction of a sender delivering a message to a receiver. The Schramm model consists of three main components: source (encoder), recipient (decoder), and message. The model suggests that the source “encodes” the message into a format that can be understood by the targeted recipient, a person or group of persons who must also have the ability and means to “decode” the message.

The “message” component is defined as information that can be expressed through words, characters, symbols, or other nonverbal means.

Schramm’s model also assumes that the recipient’s reaction to the received and decoded message is also essential through a reply that demonstrates the effectiveness of the message and information. Let's apply Schramm’s model to a real-world situation. Consider a stand-up comedian who tells a joke and hears no laughter (or response). Somewhere along the way, the message failed, probably due to improper encoding or the inability of the receiver to decode (or “get”) the joke.

“Getting” the joke is only half of the implication of Schramm’s model. It is equally important to express a reaction back to the sender, which depends on a symbiotic interaction that requires encoding, interpretation, and decoding. You can think of this as being like the use of codes for espionage: a spy in the field sends a coded message back to headquarters, where the receiver must possess the ability to interpret the message using a codebook. Again, like Berlo’s model, Schramm’s model assumes that these variable abilities to encode, interpret, decode, and provide verification of the message are necessary to engage in successful communication.

Transactional Model

Dean Barnlund (1970) introduced a complex transactional model of communication that implies a constant interaction between senders and receivers of information.5 Barnlund’s model suggests that individuals simultaneously engage in sending and receiving information through multiple messages and multiple forms of expression. These cues can be semiotic, verbal or nonverbal, conscious or unconscious, public or private. Like Schramm and others, Barnlund’s model also recognizes the importance of encoding and decoding.

Barnlund’s model also recognizes the influence of “noise” that interferes with transmitting and receiving these constant messages, including external noise, physiological/biological interference, and psychological noise. As an example of external noise, you may be present in a lecture that contains a lot of valuable information, but that content means nothing if your lab partner is loudly playing heavy metal music on his cell phone. The “noise” in Barnlund’s model isn’t limited to external and obvious interference, as it can take physiological/biological forms that are invisible to the eye, such as daydreaming, hunger, fatigue, emotion, or lack of context. Finally, psychological noise might include inner dialogue or random thoughts.

Another key aspect of Barnlund’s model is the worldview of the participants who exchange messages. Each individual is influenced by a contextual framework that filters and influences messages. The elements of this contextual framework are as follows:

• Epistemology: the way we learn and gather information

• Ontology: our core beliefs about what is real and true

• Axiology: our value system, or what we believe is right and wrong

• Cosmology: the way we see ourselves in relation to the universe (i.e., religion)

• Praxeology: our habits and preferred methods of acting

According to Barnlund, these variables of human existence are wide-ranging, and their effects on communication between senders and receivers are equally wide-ranging. More importantly, these filters seem to act in concert with—and compete with—a constant stream of messages at the same time.

For example, imagine the CEO of your company standing before an auditorium of employees as she shares the latest quarterly report. Aside from the bottom-line figures, policy updates, general announcements, and pep talk, there are countless other messages being sent, processed, and reacted to simultaneously. Each individual in attendance filters those messages through their own unique perspective, worldview, value system, and knowledge. As the CEO speaks, there may be two people whispering to each other, three or four people yawning (setting off a Pavlovian “yawn-off” for those who notice it), and maybe more than a few people slouching in their seats. According to the transactional model, each individual is sending a message based on their condition and the way they filter the messages delivered by the CEO, who also receives and processes these messages as feedback or divergent or unassociated communication (“I know Bob was working late last night, so he’s yawning because he’s tired”). As you can see, messages are sent to and from both the CEO and the employees. The same model can be applied to other scenarios, such as college lectures, sporting events, performing arts, and so on.

The feedback element between senders and receivers in the transactional model may be limited or delayed when applied to other channels of communication, but it still exists. When a message is sent over social media, for example, the filtering and responses may be delayed, but they are often shared through comments, emojis, or even silence. Senders (even those who send in reply) are constantly evaluating and quantifying such reactions, which may alter their communication accordingly.

The transactional experience may seem more complicated as a scientific model or theory, but it does address the reality of various influences on communication between individuals—and large groups.

Contemporary Studies

Modern communications models, such as the constructionist model, are based on the theories of Richard Lanham (2003) and Erving Goffman (1959), who suggested that the packaging of messages and the performance of the individuals who send or receive them are most important.6

The constructionist model emphasizes that the process of communication is the message itself, as the framing, context, rhetoric, and style become more important than the content of the message. Additionally, the packaging of the message cannot be separated from the social or historical context of its source.

To illustrate, imagine a dear friend delivering a heartfelt obituary sermon over a fallen comrade at a funeral. If the speaker is chewing gum and wearing a swimsuit, the content of the sermon becomes less important to those in attendance. Simply put, the presentation of the message is the message.

The constructionist model is a relatively new area of communications theory that is integrated with other fields of study, including psychology, sociology, and philosophy.