The main reason that change fails to occur in the first placeon any scale, and is not sustained when it does, is that the infra-structure is weak, unhelpful, or working at cross-purposes. By theinfrastructure I mean the next layers above whatever unit we arefocusing on. In terms of successive levels, for example, a teachercannot sustain change if he or she is working in a negative schoolculture; similarly, a school can initiate and implement successfulchange, but cannot sustain it if it is operating in a less than helpfuldistrict; a district cannot keep going if it works in a state that isnot helping to sustain reform.