Collaborative writing

In 5th grade we're learning about progress and Moore's law through a study of the history of ipods.  It's lots of fun, with kids researching individual models 2001 - present using both wikipedia as an entry point and Apple's press release library for primary source verification.  After the research about release date, capacity, features and price, and creating a timeline, the students have to collaboratively write a script for a ipod history podcast.

It's been a challenge for a number of groups.  Though we're all on google docs, and we've divided up the script into parts,  I'm struggling to model and show strategies for collaboratively writing high quality text.  We've had conversations about the need to write collaboratively, how much of what we read nowadays is collaboratively written, but talk is cheap.  I need to model an effective approach.  Am I stepping too far out of my discipline as a technology integrator?