Why have a chapter on theory in a beginning public relations principles textbook? Whereas most textbooks describe the state of public relations, its history, its practices, and its processes, we believe that it is also important to provide some context about how and why public relations is practiced as it is. More important, theory helps us make the practice of public relations more effective for organizations and society.

Theories are used to explain or predict the way things work or happen. They present an understanding of the relationship between various actions and events. As a public relations practitioner, you will need to build a set of theories to use and refine as you apply professional skill to the test of doing public relations.

There is no single theory to guide you. This chapter looks at several theories, which are categorized in three areas: relationships, cognition and behavior, and communication.

Another way to build an understanding of public relations is by using typologies and models. This chapter discusses a typology of roles: practitioners as managers and as technicians. Models of public relations show the interaction of two key concepts of public relations: communication and research. We provide a look at the four original models of public relations and how they have been tested and improved since their inception, and we note more recent models.