Instruct: Classify Amazon reviews into positive or negative sentiment
Query: How do you know what you know?

Second-Hand Knowledge: An Inquiry into Cognitive Authority (Contributions in Librarianship and Information Science)Primary knowledge, the things we know because we have personally experienced and/or verified them, accounts for a tiny sum of what we believe to be true. Most of what we 'know' we accept as true based on some form of proxy authority. This excellent, though dense, work discusses quite comprehensively and understandably the various ways and varying degrees in which we elevate 'second hand knowledge' to fact. Absolutely worth reading.