Action research is a cyclical process that involves planning, action, and evaluation. It was conceptualized by Kurt Lewin as a way to promote effective and permanent social change. The process involves three steps - unfreezing, where a problem is recognized; changing, where new behaviors are explored and tested; and refreezing, where successful changes are adopted. Action research engages the client in problem diagnosis, learning new behaviors, and evaluating results in collaboration with a change agent. The goal is to establish a self-sustaining process for ongoing improvement within the client system.