Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Overpriced and under-researched

Although anything Aiken is usually a given 5-star item for me, this book is a 4-star disappointment. It contains errors, which is unforgivable, considering that there aren't even that many details for the author to have spent his time researching.It is just not worth the price. Could be Mr. Torres has taken advantage of Clay and his fans.