This document discusses source evaluation and authority. It argues that authority is constructed within communities and depends on context. Standard criteria and checklists are insufficient for evaluation and need to be contextualized. True evaluation requires expertise and can be difficult due to confirmation bias and backfire effects. The document provides examples of lesson plans to teach source evaluation, including considering different perspectives, finding original sources, and comparing across sources rather than relying on judgments of a single source. Evaluation focuses on understanding authority within knowledge communities rather than viewing information as an objective commodity.