From day one of high-school English class, we have been told that it’s important to know our audience. Is it really? Why? Can we really know our audience? Or is today’s manual audience too diverse to get any kind of handle on it? How can we begin to identify our users-where do we find them? And what should we ask them when we do find them? This chapter explores all these questions, and also takes a look at what the research tells us about who reads a manual.