The model has no answers to copy. It has to invent the categories.
M4 · Finding Groups Nobody Labeled
With no labels, a model still has one move: measuring how far apart two things are. That one move builds everything here. You will run k-means by hand until it stops, see the shapes it gets wrong, cut a tree of merges at a sensible height, and meet a method that is allowed to answer nowhere. Then the chapter stops grouping and starts squeezing, from a rotation that keeps the widest view to a grid of scores rebuilt from two thin tables. It ends by burying real groups under columns that mean nothing.
- Near Means Similar
- Who Is Nearest
- k-Means, Step by Step
- Where k-Means Breaks
- How Many Groups Are There?
- Clusters Inside Clusters
- Density, Not Centers
- PCA Is a Rotation
- Maps of High-Dimensional Data
- Points That Belong Nowhere
- A Grid With Less in It
- The Curse of Dimensionality