Part 1. Definition
Given reviews from Amazon, classify those review based on their content into two classes: Negative or Positive.
Part 2. Example
I've read this book with much expectation, it was very boring all through out the book
Answer: Negative
Explanation: Review writer does not like the book because it was boring, therefore it is a negative review.
Part 3. Exercise
Usually I write a review only if I dislike something about a book. I rarely bother to write good reviews, because every book gets so many of them. In this case, however, I have to make an exception. For any fan of hard science fiction, "Pushing Ice" is AWESOME! It's got everything: realistic characters, solid physics and astronomy, believable near-future society (circa 2050), glimpses of far future society (circa 20,000 A.D.), some REALLY far future, aliens which are somewhat comprehensible, aliens which are completely beyond comprehension, rivalry, broken friendships, betrayal, marooning in space (on multiple levels), struggle for survival, etc. Even asteroid mining and that perennial "stranded in space" trick - using electric motors as generators :)
Answer:
Positive