This project work deals with reality mining and decision tree. Reality mining is the collection and analysis of data where human social behavior is analyzed through machine-sensed environment, with the goal of identifying predictable patterns of behavior. Classification is the process of finding a model that describe and distinguishes data classes, with the purpose of using model to predict the class of objects whose class label is unknown. A decision tree is a decision support tool that uses a tree-like graph or model of decisions and their possible consequences, including chance event...