This chapter considers the interrelations among three psychological principles-audience tuning, aboutness, and shared reality. It reviews some examples of audience tuning and its biasing effects on subsequent knowledge and evaluations. The chapter explains the aboutness principle is described and is used to understand why audience tuning introduces biases. It also considers the principle of shared reality and discusses how tuning about some topic to an audience creates a shared reality with them. It is this shared reality that transforms audience- tuned messages into seemingly objective and accurate statements on the topic. Communicators take into account both personal characteristics of their audience, such as their background knowledge or attitudes, and momentary situational factors such as their audience's vantage point or current state of comprehension. According to the Oxford English Dictionary, both words are rooted in the Late Latin and have come to signify an elementary distinction between kinds of knowledge.