Instruct: Classify a given Amazon review as either positive or negative.
Query: not very helpful

Contrary to the other reviewer I did not find this book very helpful at all. This may be due to the fact that whatever I was looking for I did not find in there. If you just need basic vocabulary this book might be alright for you. If you, however, intend to use it for more professional purposes, you might find it not so suitable. It is an interesting approach, but personally I'm happier with dictionaries and learning material from Collins / Pons, who tend to produce books which cost less than Longman's and are better.