Contents 1 Introduction 1 11 What Is Data Mining? 4 12 Motivating Challenges 5 13 The Origins of Data Mining 7 14 Data Mining Tasks 9 15 Scope and Organization of the Book 13 16 Bibliographic Notes 15 17 Exercises 21 2 Data 23 21 Types of Data 26 211 Attributes and Measurement 27 212 Types of Data Sets 34 22 Data Quality 42 221 Measurement and Data Collection Issues 42 222 Issues Related to Applications 49 23 Data Preprocessing 50 231 Aggregation 51 232 Sampling 52 233 Dimensionality Reduction 56