The document discusses biases made by authors and how to identify them. It defines bias as an author expressing their own opinion on an issue without presenting enough evidence, which can be influenced by personal beliefs and experiences. It contrasts biased and unbiased writing, with the latter focusing on a fair presentation of both sides of an issue rather than just one side. To determine an author's biases, the document advises examining the use of evidence and diction, where diction refers to words that convey the author's stance.