The concept of action research arises in the behavioural sciences and is obviously applicable to an examination of human activity systems carried out through the process of attempting to solve problems. This core is the idea that the researcher does not remain an observer outside the subject of investigation but becomes a participant in the relevant human group. The researcher becomes a participant in the action, and the process of change itself becomes the subject of research. In action research the roles of researcher and subject are obviously not fixed: the roles of the subject and the practitioner are sometimes switched: the subjects become researchers... and researchers become men of action.

p. 152 as cited in: R.L. McCown (2001) "Learning to bridge the gap between science-based decision support and the practice of farming". In: Aust. J. Agric. Res., Vol 52, p. 560-561 - Systems Thinking, Systems Practice, 1981