Sister Callista Roy's Adaptation Model views the person as an adaptive system that interacts constantly with the environment. The person's main task is to maintain integrity in the face of environmental stimuli through integrated, compensatory, or compromised adaptation. The model assesses a person's physiological, self-concept, role function, and interdependence adaptive modes and can be used in research, practice, education, and administration settings. While comprehensive, the model has been criticized for conceptual complexity and limitations in addressing humanistic perspectives.