Working wall - The wall should exemplify the writing process from the 'reading as a writer' stage to the 'nearly finished' stage. Final presentations can be displayed in public areas of the school or in anthologies, portfolios or folders. The wall represents a workshop approach to writing - where the 'tools of the trade' are accessible, and added to, as the process develops. It is a good idea to allow children to make contributions to the wall; post-it notes are an ideal resource for this.
This a useful link to a site that better explains what bottom-up theory is and how it's used. Personally, I prefer a more integrative approach to literacy. By dividing literacy up into such distinct pieces, a lot of the authenticity of literacy is lost.