Are we supposed to read both introductions to Chaucer, as assigned? (I have a 1st printing). I thought maybe it was a mistake, but didn't see any correction for it.
The intro is scheduled in the Norton English, but p. 1696-1698 of the Norton Western are also scheduled, which are a portion of that introduction.
Probably both are assigned because they are written by two different scholars and each has something different to contribute to your understanding of Chaucer. However, if you can only read one, I'd go with the English Literature anthology introduction. :-)