Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Subtract a Star

What a terrible textbook. I can't begin to tell you how bad it is. There is no explanation for anything. I don't know why people assume we already know what they are supposed to be teaching. The whole point is to LEARN not review. The explanations are so short, as if they expect you to just grasp it. I haven't even bothered looking through it, except for doing the homework. It won't help...