Machine learning gives us a way to trick machines into behaving as if we'd spent a lifetime programming them with hundreds of complex regular expressions or algorithms.
We can teach a machine to respond to patterns similar to the patterns defined in regular expressions by merely providing it examples of user statements and the responses we want the chatbot to mimic.
And the "models" of language, the FSMs, produced by machine learning, are much better.
They are less picky about mispelings and typoz.

And machine learning NLP pipelines are easier to "program."
We don't have to anticipate every possible use of symbols in our language.
We just have to feed the training pipeline with examples of the phrases that match and example phrases that don't match.
As long we label them during training, so that the chatbot knows which is which, it will learn to discriminate between them.
And there are even machine learning approaches that require little if any "labeled" data.

We've given you some exciting reasons to learn about natural language processing.
You want to help save the world, don't you?
And we've attempted to pique your interest with some practical NLP applications that are revolutionizing the way we communicate, learn, do business, and even think.
It won't be long before you're able to build a system that approaches human-like conversational behavior.
And you should be able to see in upcoming chapters how to train a chatbot or NLP pipeline with any domain knowledge that interests you -- from finance and sports to psychology and literature.
If you can find a corpus of writing about it, then you can train a machine to understand it.

The rest of this book is about using machine learning to save us from having to anticipate all the ways people can say things in natural language.
Each chapter incrementally improves on the basic NLP pipeline for the chatbot introduced in this chapter.
As you learn the tools of natural language processing, you'll be building an NLP pipeline that can not only carry on a conversation but help you accomplish your goals in business and in life.
