Different approaches to practice development are associated with different assumptions, and these need to be made explicit if practice development is to be transparent, rigorous and systematic in its intentions and approaches. A practice development methodology underpinned by critical social science is advocated because it focuses on achieving sustainable change through practitioner enlightenment, empowerment and emancipation and an associated culture, rather than focusing only on technical practice development. Implications of different worldviews about practice development for facilitation and outcome evaluation are highlighted. Emancipatory practice development underpinned by critical social science is argued as synonymous to emancipatory action research.