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Intermediate 20 min readModule: Module 4: Supervised Learning (Regression & Classification)

Supervised Learning: Regression, Classification & Random Forests

Train predictive models using Linear Regression, Logistic Regression, and Random Forest ensembles with Scikit-learn.

What You Will Learn in This Lesson

  • Linear Regression for continuous numerical predictions (housing prices)
  • Logistic Regression for binary classification probabilities (fraud detection)
  • Decision Trees and Random Forest ensembles for tabular data dominance

Introduction & Core Concept

Supervised Learning algorithms learn a mapping function from input features (X) to output labels (y) based on example pairs of inputs and outputs.
WHY DOES THIS MATTER IN THE REAL WORLD?

Random Forests combine hundreds of randomized decision trees to produce robust predictions that resist individual tree overfitting.

Linear Regression Prediction Model

python
python
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import numpy as np
# Linear Model: y = weight * x + bias
x = np.array([1.0, 2.0, 3.0, 4.0, 5.0])
y = np.array([2.1, 3.9, 6.2, 8.0, 10.1])
# Fit slope via ordinary least squares
weight, bias = np.polyfit(x, y, 1)
print(f"Trained Model: y = {weight:.2f}x + {bias:.2f}")
# Predict for x = 6
predicted = weight * 6 + bias
print(f"Predicted value for x=6: {predicted:.2f}")

Line-by-Line Technical Breakdown

1Evaluation metrics: Use RMSE/MAE for regression and Precision/Recall/F1-Score for imbalanced classification.

Try It Yourself (Interactive Editor)

Modify the code in real-time and click Run to test live browser output and console logs.

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Interactive Live Code

Industry Best Practices & Professional Standards

  • Never evaluate classification accuracy alone on imbalanced datasets (e.g. 99% non-fraud vs 1% fraud).

Lesson Summary & Core Takeaways

  • Supervised learning maps historical features to future numerical and categorical predictions.