Summary

In this chapter, we talked about the importance of striking a balance between bias and variance and minimizing error. Next, we saw the concept of k-fold cross-validation and how to implement it in Python to prevent overfitting. We learned the importance of cleaning data and normalizing it before processing it. We then saw an example to determine the popular pages of a website. In Chapter 9, Apache Spark - Machine Learning on Big Data we'll learn machine learning on big data using Apache Spark.