[MOSAIC] grades in reading workshop

[Cindy]

I'm really having difficulty with how to assign grades in reading workshop.  Can someone help me with that?  I want to switch completely over to reading workshop this year and toss my basal.  Also, I'm personally struggling with giving E's to students who are reading two grade levels below where they should be reading.  At the same time, you hate to fail them, but an "E" gives an unreasonable picture of the child as a reader.  How do you handle this?
Cindy/VA/2nd