โ† Artificial Intelligence & Machine Learning learning path
Artificial Intelligence & Machine Learning ยท Module 7 of 10

Unsupervised learning

Find structure in unlabelled data.

๐Ÿ“– Key ideas

  1. Clustering groups similar items: k-means, DBSCAN, hierarchical.
  2. Dimensionality reduction simplifies data: PCA, t-SNE, UMAP.
  3. Anomaly detection finds unusual records (fraud).
  4. Association rules find items bought together.
  5. Choose k with the elbow method or silhouette score.
๐Ÿ’ก Real-life example: Clustering is a teacher grouping students by interests without being told the groups.
k-meansClustering into k groups
PCAPrincipal Component Analysis
Anomaly detectionFinding outliers
Elbow methodChoosing number of clusters