Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Good, useful reference

This rates 5 stars for my purposes. It identifies birds, as it is supposed to do. Maybe I would rate it lower if I knew more about birds, and compared this books with 5 similar books with the same stated purpose.Other books have much more information, but would one want to carry around a much larger, heavier book? This book is for a novice. Others should get a small book like this to carry around, and a more thorough book to keep at home.