This module bridges theory and practice by guiding students through building a complete decision tree classifier from scratch using the ID3 algorithm. Students learn how ID3 uses entropy and information gain to make intelligent splitting decisions, implement the full recursive tree construction process including handling leaf nodes and preventing overfitting, and master essential model evaluation techniques using training/testing splits, confusion matrices, and cross-validation. The hands-on lab challenges students to implement their own ID3 decision tree classifier without relying on libraries, train it on a real-world dataset like Iris or mushroom classification, and evaluate its performance with professional metrics—giving them both a working classifier and deep understanding of what happens "under the hood" of any decision tree library they'll use in the future.

This module transforms students' decision tree knowledge into production-ready machine learning systems by tackling real-world data challenges and advanced ensemble techniques. Students learn to handle continuous numerical attributes through entropy-based discretization, implement strategies for dealing with missing data, and build random forest classifiers that combine multiple trees to dramatically improve accuracy and robustness through bootstrap aggregating and feature randomness. The module culminates in practical deployment skills including model serialization for persistence, creating user-friendly interfaces for predictions, and applying complete ML pipelines to real-world problems like credit risk assessment or customer churn prediction. By the end, students have built a deployable ML application with a command-line interface, compared single trees versus ensemble performance, and gained the skills to integrate machine learning models into production Java applications.