Hello Reader, The book presents a classification problem in data mining using decision trees.Data mining is the process of analyzing data from different perspectives and summarizing it into useful information - information that can be used to increase revenue, cuts costs, or both. Classification of large databases is an important data mining problem. Many classification algorithms have been propose, but so far there is no algorithms which uniformly outperforms all other algorithms in terms of quality. SLIQ achieves comparable classification accuracy but produces small decision trees and has small execution times.