“A word is not the same with one writer as it is with another. One tears it from his guts. The other pulls it out of his overcoat pocket.” This is how Charles Peguy described writing individual words. The same thing is true of chapters and whole books. At times, it felt like I was pulling this book out of my overcoat pocket. At other times, it felt like I was tearing it from my guts. It seems appropriate to acknowledge everyone who contributed to the long process, either by loaning me an overcoat or by helping me clean up my spilled guts.

Many kind people helped me on the long path I took to gain the experience and skills required to write this book. My parents, David and Becky Tuckfield, gave me so many gifts, starting with life and education, and continued to believe in me, encourage me, and help me in many other ways too numerous to list here. Scott Robertson gave me my first job writing code, even though I was unqualified and not very good. Randy Jenson gave me my first data science job, again despite my inexperience and limitations. Kumar Kashyap gave me my first chance to lead a development team to implement algorithms. David Zou was the first person to pay me for writing an article ($10 minus PayPal fees for 10 short movie reviews), and that felt so good, it put me on a path to writing more. Aditya Date was the first person to suggest that I write a book and gave me my first chance to do so.

I also received encouragement from many teachers and mentors. David Cardon gave me my first chance to collaborate on academic research, and taught me many things during that process. Bryan Skelton and Leonard Woo showed me examples of what I wanted to grow up to be. Wes Hutchinson taught me crucial algorithms, like k-means clustering, and helped me better understand how algorithms work. Chad Emmett taught me how to think about history and culture, and Chapter 2 is dedicated to him. Uri Simonsohn showed me how to think about data.

Some people helped to make the process of writing this book a joy. Seshu Edala helped me adjust my work schedule to be able to write, and provided constant encouragement. Alex Freed was a joy to work with during the editing process. Jennifer Eagar, via Venmo transfer months before initial publication, unofficially became the first person to buy a copy of the book; that was appreciated during a difficult time. Hlaing Hlaing Tun was supportive, helpful, sweet, and encouraging at every step.

I cannot repay all of these debts of gratitude, but at least I can say thank you. Thank you!