Explain the difference between Supervised and Unsupervised Anomaly Detection.

Updated May 5, 2026

Short answer

Supervised uses labeled data; unsupervised finds patterns in unlabeled data[cite: 1].

Deep explanation

Supervised models are trained on known examples of 'normal' and 'anomaly'. Unsupervised models assume anomalies are rare and located in low-density regions[cite: 1].

Real-world example

Unsupervised is used for detecting new types of zero-day cyber attacks[cite: 1].

Common mistakes

  • Using supervised learning when the 'anomaly' class is too small to learn from[cite: 1].

Follow-up questions

  • What is semi-supervised detection?

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