Sister Callista Roy developed the Adaptation Model in 1976. This model comprises the four domain concepts of person, health, environment, and nursing and involves a six step nursing process. Andrews & Roy (1991) state that the person can be a representation of an individual or a group of individuals. Roy's models sees the person as "a biopsychosocial being in constant interaction with a changing environment" (Rambo, 1984). The person is an open, adaptive system who uses coping skills to deal with stressors. Roy sees the environment as "all conditions, circumstances and influences that surround and affect the development and behaviour of the person" (Andrews & Roy, 1991). Roy describes stressors as stimuli and uses the term 'residual stimuli' to describe those stressors whose influence on the person is not clear (Andrews & Roy). Originally, Roy wrote that health and illness are on a continuum with many different states or degrees possible (Rambo, 1984). More recently, she states that health is the process of being and becoming an integrated and whole person (Andrews & Roy). Roy's goal of nursing is "the promotion of adaptation in each of the four modes, thereby contributing to the person's health, quality of life and dying with dignity" (Andrews & Roy). These four modes are physiological, self-concept, role function and interdependence.
Roy employs a six-step nursing process which includes: assessment of behaviour, assessment of stimuli, nursing diagnosis, goal setting, intervention and evaluation. In the first step, the person's behaviour in each of the four modes is observed. This behaviour is then compared with norms and is deemed either adaptive or ineffective. The second step is concerned with factors that influence behaviour. Stimuli are classified as focal, contextual or residual (Rambo, 1984). The nursing diagnosis is the statement of the ineffective behaviours along with the identification of the probable cause. In the fourth step, goal setting is the focus. Goals need to be realistic and attainable and are set in collaboration with the person (Andrews & Roy, 1991). Intervention occurs as the fifth step, and this is when the stimuli are manipulated. It is also called the 'doing phase' (Rambo). In the final stage, evaluation takes place. The degree of change as evidenced by change in behaviour, is determined. Ineffective behaviours would be reassessed, and the interventions would be revised (Andrews & Roy).
Roy's model of nursing sees an individual as a set of interrelated systems, biological, psychological, and social. The individual tries to maintain a balance between each of these systems and the outside world. However, there is no absolute level of balance. According to Roy we all strive to live within a band where we can cope adequately. This band will be unique to an individual. The adaptation level is the range of adaptability within which the individual can deal effectively with new experiences.
Callista Roy maintains there are four main adaptation systems which she calls modes of adaptation. She calls these the physiological system, the self concept system, the role mastery system, and the interdependency system.