Free Write Question

I wonder if we could get some conversation going on the blog about managing Free Writes.  Today I had my Novices (low and mid) do a 10-minute free write.  A few were frustrated because they got cut off by the time and had a lot left of the story to write.  I was kind of curious to see how much they’d produce if I let them go…on the other end, I had one student who was completely blocked by the openness of the task (even though I did have a list of verbs from the story on the screen, plus all the supporting vocab on the walls).  In between, I had a bunch of students doing bullet-point lists of phrases.  I love seeing the variety of styles and levels of acquisition, but I wonder if other people have these kinds of results and what they do to accommodate different needs during free writes.