03 · How learning succeeds and fails

Broad intuition · Study map 10 of 85

Clustering, compression, and anomalies

Suggested preparation: Linear models, trees, neighbors, and ensembles

Picture it

Clustering draws neighborhoods; dimensionality reduction finds a smaller set of coordinates; anomaly detection asks what does not fit. None of these automatically discovers the categories a human cares about.

What to understand

  • k-means, density clustering, PCA, and autoencoders
  • Distances, scaling, outliers, and the limits of visualization

Follow the references

  1. 1 · Documentation

    scikit-learn · Unsupervised learning ↗

    Use clustering, decomposition, and novelty detection. Compare their assumptions on the same small dataset.

You understand it when…

Why can changing feature units completely change a clustering result?

This is a study map. Follow the reference for the full explanation; use the question to test your mental model. Browse the reference shelf.