When communication researchers make claims about the relationship of media to individuals or society, they use the term media to mean a variety of things. For example, a researcher might try to prove the claim "television causes X," where X might be anything from aggressive behavior to bad vision or a crisis in a sense of self. In this case, is the researcher talking about the television signals in the air, people who work at television stations, people who produce or act in television programs, the television programs themselves, television receiving sets, or some or all of these things?