1. Definition of a model
2. Functions of a model
3. Evaluation of a model
4. Some early communication models
- Lasswell's Model
- The Gerbner Model.
1- Definition of a model:
A model is not an explanatory device by itself, but it helps to formulate theory. It suggests relationships between variables.
A model provides a frame within which we can consider a problem, even if in its early versions it does not lead to successful prediction. Failure of a model when it is tested may lead to an improved model.
2- Functions of a model:
There are four distinct functions of models: organizing, heuristic, predictive and measuring. The organizing function of a model is seen in its ability to order and relate data, and to show data similarities and connections that had not previously been perceived. A model can be heuristic device that may lead to new unknown facts and methods. The model implies prediction that can be made, if it explains something that was not understood before.
Models allow a rang of predictions, from the simply yes or no type to completely quantities predictions dealing with when or how much.
When a model allows us to make completely quantitative prediction, it becomes related to measurement of the phenomena we are interested in.
3- Evaluation of a model:
One can evaluate a model by answering the following questions: - How general is a model?
- How helpful is it in discovering new relationships, facts or methods?
- How accurate are the measurements that can be developed with the model? - How original is the model? Or how much new insight does it provide? - What is the model's simplicity, economy of means?
- How real is the model? To what degree may we rely on it as a representation of physical reality?
3- Some early communication models:
(1) Lasswell's Model:
It is considered the early verbal model in communication. It focuses attention on important aspects of communication.
In Which Channel
With What Effect.
Who: The "Who" raises the question of the control of the messages (e.g. gatekeeper).
Says What: is the subject of content analysis (e.g. content analysis of TV programs).
In Which Channels:
It implies that more than one channel can carry a message. Communication channels are studied in media analysis.
To Whom: It deals with the receiver and audience analysis.
(e.g. viewers attitudes towards presidential elections).
With What Effect: This is the main goal of the communication process (e.g. communication credibility, changing people's attitude, behavior…etc).
(2) Shanon&Weaver (The Information Theory):
In this model, the information source produces a message.
The message may consist of spoken or written words, music, pictures, and so on.
The transmitter converts the message to a signal suitable for the channel to be used.
The channel is the medium that transmit the signal from the sender to the receiver. ( see examples in Page 50-52).
The destination is the person or thing for whom the message is intended. (e.g. the listener, the reader, the viewer, the computer..).
Feedback allows the system to make corrections in its own operation. In mass medium the audience feed back has many forms that help the source to correct subsequent outputs. Letters, phone calls, from readers or listeners, increase or decrease in sales, audience ratings are some examples of mass media feedback.
Noise is defined as anything added to the signal that is not intended by the information source. Noise can take many forms: distortion of sound on radio, distortion of shape or shading in TV image.... etc.
Noise can take the form of speaker's distracting mannerism-added to the signal, but not intended by the information source.
Noise can also be competing stimuli from outside the channel. Examples are a crying baby, a...