Book Image

Hands-On Recommendation Systems with Python

By : Rounak Banik
Book Image

Hands-On Recommendation Systems with Python

By: Rounak Banik

Overview of this book

Recommendation systems are at the heart of almost every internet business today; from Facebook to Net?ix to Amazon. Providing good recommendations, whether it's friends, movies, or groceries, goes a long way in defining user experience and enticing your customers to use your platform. This book shows you how to do just that. You will learn about the different kinds of recommenders used in the industry and see how to build them from scratch using Python. No need to wade through tons of machine learning theory—you'll get started with building and learning about recommenders as quickly as possible.. In this book, you will build an IMDB Top 250 clone, a content-based engine that works on movie metadata. You'll use collaborative filters to make use of customer behavior data, and a Hybrid Recommender that incorporates content based and collaborative filtering techniques  With this book, all you need to get started with building recommendation systems is a familiarity with Python, and by the time you're fnished, you will have a great grasp of how recommenders work and be in a strong position to apply the techniques that you will learn to your own problem domains.
Table of Contents (9 chapters)

Dimensionality reduction

Most machine learning algorithms tend to perform poorly as the number of dimensions in the data increases. This phenomenon is often known as the curse of dimensionality. Therefore, it is a good idea to reduce the number of features available in the data, while retaining the maximum amount of information possible. There are two ways to achieve this:

  • Feature selection: This method involves identifying the features that have the least predictive power and dropping them altogether. Therefore, feature selection involves identifying a subset of features that is most important for that particular use case. An important distinction of feature selection is that it maintains the original meaning of every retained feature. For example, let's say we have a housing dataset with price, area, and number of rooms as features. Now, if we were to drop the area feature...