Chapter 6

Preprocessing

Before any complex modeling, you have to make your data fit to model on. This chapter covers missing features, missing values (MCAR/MAR/MNAR), outlier detection and handling, data transformations, and the structured quality assessment process that separates professional data work from notebook hacking.

• 1. Missing Features: Two Cautionary Tales→
• 2. Missing Values: MCAR, MAR, and MNAR→
• 3. When Missingness Is a Feature→
• 4. Detecting Outliers→
• 5. Handling Outliers and Transforming Data→
• 6. The Data Quality Assessment→