When people participate in a spoken conversation, they pay attention to a wide range of factors: why they’ve joined the conversation, who’s involved in the conversation, and what’s already been said. They also notice the mood of the people they’re speaking with, their facial expressions and body language, and physical factors such as background noise. In short, they consider the situation as they listen and speak. Similarly, when writers engage in written conversation, they become part of a writing situation — the setting in which writers and readers communicate with one another. Writing situations — the phrase we’ll use in this book to refer to rhetorical situations — are shaped by these and other important factors, including the sources you use and the type of document you decide to write.