Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Instructions are poor

I agree with Len Bast, the instruction are very poorly laid out and often contradict themselves. One of my biggest problems with this book was that for each telescope he suggests, he neglects to have a list of building materials and tools at the start of each chapter, which is a huge mistake. As mentioned previously, the plans quite often contradict themselves, or one of the accompanying photos or diagrams or else leave ambiguities that, to a novice builder, seem bewildering. Nevertheless, I did manage to build a working telescope from this book, so while it's not entirely useless, it could be much improved.