You need to talk about the different theorists such as Reggio Emilia, high/scope, Montessori, Steiner, and how these impact on the early years sector.
If you don't know about them you can research them on-line.
The book I linked also has some information about some of them, I find the book really useful.
http://www.amazon.co.uk/gp/product/0...=silkysteps-21