Methods of Study
Communication researchers study communication through various methods that have been verified through repetitive, cumulative processes. Both quantitative and qualitative methods have been used in the study of mass communication. The main focus of mass communication research is to learn how the content of mass communication affects the attitudes, opinions, emotions, and ultimately behaviors of the people who receive the message. Several prominent methods of study are as follows:
• Studying cause and effect relationships in communication can only be done through an experiment. This quantitative method regularly involves exposing participants to various media content and recording their reactions. To show causation, mass communication researchers must isolate the variable they are studying, show that it occurs before the observed effect, and that it is the only variable that could cause the observed effect.
• Survey, another quantitative method, involves asking individuals to respond to a set of questions in order to generalize their responses to a larger population.
• Content analysis (sometimes known as textual analysis) refers to the process of identifying categorial properties of a piece of communication, such as a newspaper article, book, television program, film, or broadcast news script. This process allows researchers to see what the content of communication looks like.
• A qualitative method known as ethnography allows a researcher to immerse themselves into a culture to observe and record the qualities of communication that exist there.
The Association for Education in Journalism and Mass Communication is the major membership organization for academics in the field, offering regional and national conferences and refereed publications. The International Communication Association  and National Communication Association (formerly the Speech Communication Association) are also prominent professional organizations. Each of these organizations publishes a different refereed academic journal that reflects the research that is being performed in the field of mass communication.
Source - Wikipedia