Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Plagued with errors

A big no-no for an instructive chess book is to have errors that make it difficult for the reader to learn the lessons. In the very first exercise, in the board figure, there is a missing knight. If I had been playing the exercises on the board, the knight would be there, but since I was trying to analyze the position based on the figure, the text made no sense. So I'm not even going to bother going through the rest of the book.