People talk about a lot of things online. There are forums and communities for almost everything under the sun, and some of them may be about your product or service. People may complain, or they may praise, and you would want to know which of the two they're doing.

This is where sentiment analysis helps. It can automatically track whether the reviews and discussions are positive or negative overall, and it can pull out items from either category to make them easier to respond to or draw attention to.

Over the course of this chapter, we'll cover a lot of ground. Some of it will be a little hazy, but in general, here's what we'll cover:

Before we go any further, let's learn what sentiment analysis is.