Instruct: Classify Amazon reviews into positive or negative sentiment
Query: A little silly, but fun

This book is a sort of training manual for MacGyver wannabes. It's a collection of low-tech, cheap little projects that one can do in order to simulate "real" technology. You could certainly use some of these in an emergency, which is what the author suggests, but that's not really the point of the book in my view.The real use would be for kids-- or, even better, kids and parents-- who want to mess around with some every day items in ways they haven't previously, have some fun, and enjoy some "Wow! Look at that!" moments. Had the author designed the book explicitly for that purpose, many of the negative reviews here wouldn't have been written.So, the book is both pretty silly and enjoyable, but it's not any sort of survival manual. A word of advice: Avoid the sequel; the author used all of his good ideas in this volume.