This concept, used in our daily language, is inconspicuous. For an understanding of change in people, teams and organisations it is of outstanding prominence!
Each of the systems named above expects something in every current situation: that which seems impossible and excluded (“The stone cannot fly away by itself.”), that which is taken for granted (“I own this house.”) and that which will probably or less probably occur (“Tomorrow we will still be friends.”). These three aspects of expectation determine each system’s viewpoint of the world. They can be conscious or unconscious, manifest or latent, written or unwritten. Expectations can be very situational; however, most of them are very stable and form the internal structure of the system. Systems try to stabilise these expectations because they are coagulated complexity reduction. Who would like to imagine that the rules of the road changed daily and one had to find out during breakfast how one needed to cycle.
With some justification one can say that the sum of all expectations form the ‘identity’ of a system. So it is not its (fixed) nature but developed and thus, in principle, expectations of the environment and of itself (!) are changeable. Changes, therefore, always consist of the change of self-generated expectations (“Do I really need the praise from the boss?”, “Do things always have to run according to my perception of fairness?”, “Is controlling really unavoidable?”, “Do we really have to reach consensus about everything?”) If actions/decisions are changed but the expectations are not, then the changed actions/decisions will not deliver the desired results either!