I was actually a trainer at my old school where we piloted this program. I really had success with it. However, the district I'm now at does not use it. I've tried to incorporate it in my class, but it's one of those programs that really needs the vertical alignment to be successful. It's a very structured way to teach and it provides good advice on what to critique in student writing. Before this program, I could read a narrative that seemed so poorly written I didn't even know where to start! This program helps with that. It focuses very heavily on modeling, modeling, modeling. Also, the use of literature in lessons and student examples. I guess I just really liked the specificity of it. Some teachers felt it stifled creativity because it was too structured. I think any teacher could make it work for them though.
