Data science is a hot and growing field, and it doesn’t take a great deal of sleuthing to find analysts breathlessly prognosticating that over the next 10 years, we’ll need billions and billions more data scientists than we currently have. But what is data science? After all, we can’t produce data scientists if we don’t know what data science is. According to a Venn diagram that is somewhat famous in the industry, data science lies at the intersection of:

• Hacking skills
• Math and statistics knowledge
• Substantive expertise.

Although we originally intended to write a book covering all three, I quickly realized that a thorough treatment of “substantive expertise” would require tens of thousands of pages. At that point, we decided to focus on the first two. Our goal is to help you develop the hacking skills that you’ll need to get started doing data science. And also to help you get comfortable with the mathematics and statistics that are at the core of data science. This is a somewhat heavy aspiration for a book.