The question as it is applied to television typically becomes either, How is society different because television is part of it? or, How are individuals or specific groups of people different because they live in a world in which television is available? The first of these questions may be thought of as a matter of media effect upon society, while the second is a matter of media effect upon the development or status of individual people.

Effects of television, then, may be social or psychological and developmental. They may also be short term or long term. Walter Weiss, writing in the second edition of the Handbook of Social Psychology (1969), discussed effects literature under ten headings: (1) cognition, (2) comprehension, (3) emotional arousal, (4) identification, (5) attitude, (6) overt behavior, (7) interests and interest-related behavior, (8) public taste, (9) outlook and values, and (10) family life.

For the most part, such effects, however they are characterized, have been studied in a haphazard fashion characterized by the funding priorities of governments and nonprofit foundations. For example, there have been many efforts to assess the effect of the availability of television upon the developmental processes in children. A case in point concerns the British Home Office, which in 1963 established its Television Research Committee with sociologist J.D. Halloran as its secretary. The effects of television were to be studied as both immediate and cumulative, with separate attention paid to perceptions of TV, its content, and its function for viewers.

One area that has been heavily studied and produced an extensive research literature addresses the specific issue of violence, especially the connection between television treatment of violence and its manifestation in society. This work addresses whether portrayals of violent behaviors result in members of the viewing audience becoming more violent in their relationships with others. This issue is often related to other presumed connections between the models projected by television and various modes of perception and behavior. Thus, the manner in which women and minorities are presented in various television programs may be connected by some researchers to the ways these groups are perceived by viewers in other groups and by the group members themselves.

Just as the presence or absence of a medium or some particular of program content (e.g., violence) can be considered capable of producing effects in an audience, so can such technological innovations as pay-per-view, satellite delivery, three-dimensional presentation, stereo sound, interactive television, the Internet, or streaming. Any of these technological innovations may be linked in a research question with special viewing populations and special samples of program materials in attempts to determine whether or not the shift in technology has an effect on subsequent behavior or attitude.

Effects research is grounded in various forms of social scientific analysis and often depends on such techniques as controlled experiments, surveys, and observations. Challenges to methods, design, or sample size are used to call results into question, and clear, incontrovertible conclusions are difficult to establish. Particularly with regard to research focused on children or on the role of televised violence, these philosophical and scientific difficulties have made it almost impossible to develop broadcasting policies based on research findings.