Joshua Dyal said:
But that's a bit of a strawman.
Yep.
Some of those changes did have to be made because of the media involved. Others did not, and were made for some other reason.
How's audience expectation grab you?
It's hardly a given that one can relate the success of the movies on the changes made to the books, though. That could very well (and in my opinion for both movies) have more to do with the strength of the original source material that showed through in spite of some of the changes that were made.
In those two cases, LotR was unfilmable as written, IMO, and therefore isn't a good example. We could debate that, but it would get us nowhere, as you will never convince me (several have tried) that LotR could have been directly translated into a palatable film. Jurassic Park, on the other hand, is debatable.
So here are what I see as the issues with the book that, good or bad, end up breaking audience expectation:
1) No romantic interest for the main character. Wasn't even a significant change, anyway.
2) Politically incorrect: two kids. 1 boy, 1 girl. In book, boy solves everything, girl only exists to cause problems. Irritated me in the book, would irritate a movie audience. Fix: Make girl older and marginally useful. Don't understand the problem, personally.
3) Hammond was a right bastard. Can't have your only senior citizen be a jerk who gets eaten by dinosaurs. Not politically correct. Bad change, but I can see why they made it. Besides, the movie focused on the dinosaurs as the villains. A mildly sympathetic human villain would have muddied the waters.
There are others, but I'm really tired and need sleep...
Mmmmmm... sleep...