Tutorial
Jun 26, 202610 min read
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Decision Trees: Entropy and Gini Impurity
You're a loan officer at a bank. Every day, applications cross your desk — income statements, employment records, credit histories. You've developed a mental ch…
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Decision Tree
Tutorial
Jun 26, 20269 min read
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Information Gain and Full Tree Construction
You found the best root split in post 01: Employed. But one split doesn't make a tree. The left child (Employed=No, 4 samples) still has a mix of Yes and No. Th…
Tutorial
Jun 26, 20269 min read
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Splitting Numerical Features in Decision Trees
You have a house and you want to know if it's worth over $300k. You know its square footage and number of bedrooms. These are numbers — 1200 sq ft, 3 bedrooms,…
Tutorial
Jun 26, 202610 min read
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Decision Tree Pruning: Pre-Pruning and Post-Pruning
You train your first full decision tree. Training accuracy: 100%. You feel great. Then you check the test accuracy: 92.98%. You feel confused. The tree memorize…
Tutorial
Jun 26, 202610 min read
0
Decision Tree Regression
You have a house. You know its square footage. How much is it worth? You could draw a straight line through the data — that's linear regression, and it works we…