Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Not worth your money

A mediocre intro into such a fascinating subject. Instead of explaining concepts and helping develop abilities to solve problems, Griffiths plays silly algebra games throughout this text. Some truly elementary material he made rather complicated, explaining the obvious but omitting points crucial for understanding. With this book, forget about any intuitive knowledge of QM. If you like the monkey business of endless calculations, this one will not get you bored. But if you simply want to learn this fabulous branch of modern physics, consider N.Zettili, "QM Principles and Applications", which I guarantee you'll find invaluable. A little note for students to whom this reading is mandatory: Save your own nerves, and get the Solution Manual - will help you a lot on the exams.