Instruct: Classify Amazon reviews into positive or negative sentiment
Query: We need a zero or a negative scale

Not only are many of the concepts extremely juvenile, but his explanations are often screwy and therefore worst than no explanation at all. He helps perpetuates many false concepts. Worst, he takes some good experiments from other books and mangles the concept. For example, in the light scattering experiment he says: "the blue light waves are trapped" but they are in fact scattered. Buy the books he takes his ideas from, don't buy this poorly reworked nonsense.