PoA movie vs. book

[huntergreen_3]

Sarah wrote:
>>In the book, Peter Pettigrew is discovered alive by
Lupin using the Maurader's Map after H/R/H had already met up with
Padfoot and Crookshanks. He then goes into the Shrieking Shack
after them. In the book, however, Harry tries to find Pettigrew in
the school one night after he (Scabbers) disappeared. Harry follows
the map by wandlight and appears to walk right past him.

Unlike the other discrepancies in the plot details, I don't see any
cinematic reasons for changing this pretty significant (in my
opinion) detail in the story line. Is anybody else bothered by
this, or does anybody have any explaination as to how this change
had ANY positive effect to the story or why the director chose this
means to an end?<<

Rebecca: (welcome to the list!)
I can't remember if this was specifically discussed either, I think 
it may have been touched on, but swallowed by other things. 
Others have already explained it very well, but to add one thing, I 
thought it helped the story to have Harry see Peter on the map at 
some point. That was a question that had been asked on the book list 
many times (why did Harry never see Peter Pettigrew on the map?) so 
the movie avoided the same argument with that scene. Also, it helped 
the shrieking shack explanation along, by giving Harry a reason to 
believe them. If they hadn't had that scene the shrieking shack scene 
would have been more difficult to adapt.