The emergence of a profession involves a range of socio-historical forces. E. Wood has shown how state intervention has contributed to the reshaping of profession in early childhood education. In the province of police education, D. White and B. Heslop highlight the often different philosophical orientations to training and development among public-sector professions. Teaching, they assert, is associated with liberal education and critical thinking, whereas policing is more commonly associated with matters of state control and the constraint of citizenship. Commenting on teacher professionalism in England, M. Barber has argued for the existence of a few distinct phases of education reform. Beginning in the 1970s with a so-called 'Golden Age' of teacher autonomy, he describes this as an era of 'uninformed professionalism'. Barber asserts that it was only after a period of intensive state intervention, involving teachers acquiring appropriate state-approved knowledge and skills, that 'informed professionalism' was to become a reality, with the profession afforded a greater degree of freedom.