In the 1960s and 1970s, the critical function of art was increasingly seen to derive from its engagement with everyday life. The power of art was more likely to be generated from art's contact with the randomness, contingency, and complexity of the world than it was to emerge from a hermetic realm of its own. This imperative produced arts that were characterized by the renunciation of controlling artistic will, the tendency to grant the viewer an active role in the process of art, and the willingness to allow chance processes and extrinsic factors to affect the meaning and appearance of works of art. But questions remained: what was to guarantee that the extrinsic factors in question were truly authentic wellsprings of raw experience? How was one to know that everyday American life had not already been "framed" by the advertising industry, the mass media, or the government? As the 1980s began, these questions became increasingly difficult to ignore.