Social work is a professional and academic discipline that seeks to improve the quality of life and subjective well-being of individuals, groups, and communities through research, policy, community organizing, direct practice, crisis intervention, and teaching for the benefit of those affected by social disadvantages such as poverty, mental and physical illness or disability, and social injustice, including violations of their civil liberties and human rights. Research is often focused on human development, psychotherapy and counselling, social policy, public administration, social program evaluation, and community development. Social workers typically undergo a systematic set of training and qualifications that are distinct from those of care workers, care assistants or social care workers, who may undertake social work roles but not necessarily have the qualifications of a professional social worker. Social workers are organized into local, national, continental, and international professional bodies. It is an interdisciplinary field that incorporates theoretical bases from economics, education, sociology, law, medicine, philosophy, politics, anthropology, and psychology.