  This brief survey analyzes the epistemological implications about the role of
observer in the interpretations of Quantum Mechanics. As we know, the goal of
most interpretations of quantum mechanics is to avoid the apparent intrusion of
the observer into the measurement process. In the same time, there are implicit
and hidden assumptions about his role. In fact, most interpretations taking as
ontic level one of these fundamental concepts as information, physical law and
matter bring us to new problematical questions. We think, that no
interpretation of the quantum theory can avoid this intrusion until we do not
clarify the nature of observer.
