Practical Recommender Systems

Chapter 8. Collaborative filtering in the neighborhood

Collaborating makes things easier, so let’s collaborate our way through this chapter.

• You’ll start by revisiting the rating matrix.
• You’ll look at the theory behind collaborative filtering.
• Collaborative filtering is done in several steps, and you’ll look at each and learn about the choices that need to be addressed.
• You’ll learn how collaborative filtering is implemented in MovieGEEKs.

This chapter introduces collaborative filtering and goes into detail about the branch of it called neighborhood-based filtering. Collaborative filtering is an umbrella of methods. What unites those is the selection of data. These filtering methods only use ratings (implicit or explicit) as the source for ...