In general, theories of public relations are divided into two major groups: communication theories and system theories. Communication theory is based on models of communication. There are four basic elements of communication: sender, message, medium and receiver. Earlier model of communication is one-way communication while the latest are two-way asymmetric and two-way symmetric models. In traditional one-way communication model the process is quite simple: the message goes from sender to receiver. In modern two-way communication model the sender also plays role of receiver and vice versa. This is he first type of communication models. According to Grunigs theory there are four models of public relations. Public practitioners believe that this models represent evolution of the science, concluding with the modern two-way theories. The first two types are based on one-way communication: press agentry/publicity model and public information model.
The first model involves persuasion and manipulation to achieve organizations desires from listeners. Persuasion and manipulation are very close to each other, but still not the same in practice. Persuasion is more ethical way of an attempt to influence persons actions and conclusions, which is usually beneficial to both parties. Manipulation is not always beneficial to the receiver of information. In fact, sometimes the audience is tricked into this information without any desire to know it. The press agentry model is the very first type of communication models. It is represented by one-way flow of information from sender to receiver in order to persuade him and influence his beliefs. The model involves propaganda function, which ethical side is very questionable since the main aim of the communication is to influence the audience.
Even though this model is quite old, it is represented nowadays in many ways. Headlines of many newspapers also belong to this type of communication: the sender of the message is trying to touch readers curiosity and skepticism in order to get his attention, even though this information may be not so useful for many of them. For example, the article which says that some celebrity cheated on her husband/boyfriend. This information can get many peoples attention, but its ethical part is very questionable as well as credibility of the source and importance of the information. The launch of new movie is also an example of this model. Press agents help their clients to achieve whatever they want from the audience with the help of this model. Even though it is highly criticized, the audience is the one who helps this model to survive due to our skepticism and curiosity.
The second type of communication model is public information model. Even though it is similar to press agentry model in its one-way communication, it differs with the information it gives to the public. The information is more truthful and credible, and is presented in more ethical way. If an organization uses this model instead of press agentry, its reputation will be better since this model is more about distributing credible and accurate information rather than manipulating audience. This communication model is a very good way to get over crisis for the company. For example, when some misunderstanding between an organization and public occurs, the organization can issue a press release where it can clearly explain the situation to the public and answer the questions arised. This model is necessary for the society as it brings the clear and accurate information to the public.