Over the years, many PR models have been proposed and developed by scholars and practitioners. However, James Grunig and Todd Hunt's 1984 book, Managing Public Relations, proposed one of the most influential and widely used classifications of PR models. This classification identified four PR models based on the direction, balance, and nature of the communication between an organization and its publics. The first model is press agentry, which focuses on generating publicity and attention for the organization without regard for truth or feedback from publics. It is one-way and asymmetrical, meaning that only messages are sent out without listening or responding to publics. This model is often used by celebrities or politicians who want to create a favorable image or hype. The second model is public information, which focuses on disseminating factual and accurate information about the organization without seeking to persuade or influence publics. It is also one-way and asymmetrical, meaning only information is provided without engaging or dialoguing with publics. This model is often used by government agencies or educational institutions who want to inform or educate publics. The third model is two-way asymmetrical, which focuses on persuading and influencing publics to accept the organization's views or actions without considering their needs or interests. It is two-way but asymmetrical, meaning communication is used to achieve its own goals without balancing or compromising with publics. This model is often used by businesses or lobbyists who want to sell or promote products or services. The last model is two-way symmetrical, which focuses on building mutual understanding and relationship between the organization and its publics without manipulating or coercing publics. It is two-way and symmetrical, meaning communication is used to foster trust and cooperation without dominating or exploiting publics. This model is often used by organizations that value social responsibility, ethics, or stakeholder engagement.