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shangkyu shin
shangkyu shin

Posted on • Originally published at zeromathai.com

Traditional Machine Learning in Practice: Learning Paradigms, Algorithm Families, and Evaluation Perspectives

Traditional machine learning is more than just algorithms. This guide explains how learning paradigms, model families, and evaluation metrics actually fit together in real systems.

Cross-posted from Zeromath. Original article: https://zeromathai.com/en/dl-traditional-ml-overview-en/


Why This Still Matters

Before deep learning, everything was built on traditional ML.

Even today:

  • it's more interpretable
  • it works better on smaller datasets
  • it’s widely used in production

If you skip this, you’re missing the foundation.


1. What ML Actually Does

Instead of writing rules:

πŸ‘‰ ML learns patterns from data

Goal:
πŸ‘‰ generalize to unseen data

This is why:

  • training accuracy β‰  real performance
  • overfitting exists

2. Three Learning Paradigms

Supervised Learning

  • input + label
  • used for classification & regression

Example:
predicting spam emails


Unsupervised Learning

  • no labels
  • discover structure

Example:
customer segmentation


Reinforcement Learning

  • agent interacts with environment
  • learns via rewards

Example:
game AI


3. Think in Algorithm Families

Don’t memorize algorithms individually.


Clustering

  • K-means, hierarchical

πŸ‘‰ grouping based on similarity


Classification

  • logistic regression
  • decision trees
  • random forest
  • SVM, KNN

πŸ‘‰ decision boundaries


Regression

  • linear regression
  • ridge / lasso

πŸ‘‰ predict continuous values


Ensemble Learning

  • bagging
  • boosting

πŸ‘‰ combine models for better performance


4. Evaluation (Most Common Mistake Area)

Classification

  • accuracy (not enough)
  • precision / recall
  • F1-score
  • ROC-AUC

Regression

  • MSE / RMSE
  • MAE
  • RΒ²

Clustering

  • silhouette score
  • homogeneity

πŸ‘‰ Metrics are context-dependent.


5. Core Insight: Generalization

Models don’t memorize.

They approximate:
πŸ‘‰ data distribution

That’s the real reason:

  • overfitting happens
  • test data matters

Final Takeaway

Traditional ML is still essential because:

  • it's interpretable
  • it's efficient
  • it's foundational

Deep learning builds on itβ€”not replaces it.


Discussion

Where do you still use traditional ML?

  • production systems?
  • feature pipelines?
  • hybrid ML + DL setups?

Curious to hear your use cases πŸ‘‡

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