Kurt Lewin theorized a three-stage model of change that has become known as the unfreezing-change-refreeze model that requires prior understanding how to be rejected and replaced. Edgar Schein provided further aspect for a far more comprehensive style of change calling this process "cognitive redefinition. " The first level is when individual is becoming encouraged to change. This period of change is built on the theory that human patterns is established by past observational learning and ethnical influences. Change requires adding new causes for change or removal of a few of the prevailing factors that are in play in perpetuating the action. It is necessary to move at night possible anxieties for change to progress. This can be accomplished by either having the survival stress be greater than the learning anxiousness or, ideally, learning stress and anxiety could be reduced.