PREFACExviii
from the reality of applying the techniques. Mahout in Action aims to be accessible, to
unearth the interesting nuggets of insight for the enthusiast, and to save the practitio-
ner time in getting work done. I hope it provides you more “a-ha!” moments than
“wha…?” moments.
S
EAN OWEN
My (Robin’s) interest in machine learning started during my days in college, back in
2006. At that time, I was working as an intern with a group of people designing a per-
sonalized recommendation engine. That group flourished and became a company
called Minekey; I was invited to join as one of its core developers. The next four years
of my life were spent implementing and experimenting with machine learning tech-
niques. Somewhere along that path, I stumbled across Mahout and started contribut-
ing as a Google Summer of Code student. The next thing I knew, I was contributing
algorithms and patches to its codebase, tuning and optimizing performance, and
helping other folks on the mailing list.
I am really fortunate to be part of a wonderful and growing community of develop-
ers, researchers, and enthusiasts of machine learning. As more and more companies
are adopting Mahout, it is becoming a mainstream library of machine learning. I
really hope you enjoy reading this book.
R
OBIN ANIL
I (Ted) came to the application side of projects from research in machine learning.
Formerly an academic, I have subsequently been involved in a number of startups,
and I have applied machine learning to all of these practical application settings.
Previously, I (Ellen) worked in research laboratories in biochemistry and molecu-
lar biology. In addition to having lots of experience with data, I’ve written extensively
on technical subjects. Throughout it all, I’ve remained fascinated by data and how it
speaks to us. I have tried to bring this insight to Mahout in Action.
Both of us see that open source only works with input from an active and broad
community of participants. A major part of Mahout’s success comes from those who
have used the software and brought their experience back to the project via discus-
sions in mailing lists, bug fixes, and suggestions.
For this reason, Mahout in Action not only provides useful explanations of code, but
also guidance regarding the concepts behind the code. This introduction to the
framework behind the code will enable you to effectively join in and benefit from the
interactive Mahout discussion. We hope this book not only helps the readers of this
book, but also helps to expand and enrich Mahout itself.
T
ED DUNNING AND ELLEN FRIEDMAN
Licensed to Jianbin Dai <djianbin@yahoo.com>