If you actually have to solve a multiclass problem, I strongly urge you to simply use OVA or AVA, and not worry about anything else. The choice between OVA and AVA is largely computational.

Machine Learning Basics Lecture 7: Multiclass Classification Princeton University COS 495 Instructor: Yingyu Liang

We get that multiclass margin is indeed the di erence between the correct label and its highest competitor.

Multiclass classification OVR and OVO: learn the discriminant functions for binary classification problems combine them to define the multiclass discriminant functions

Multiclass classification Multi-class and Multi-label Multi-class: have multiple classes, with each instance only in one class e.g., a person can only have one blood type Multi-label: have multiple classes, …

Multiclass Logistic Regression Definition (under different features): exp(w>f(x; y)) P (yjx) = P

First idea: Use K 1 classi ers, each solving a two class problem of separating point in a class Ck from points not in the class. PROBLEM: More than one good answer for green region! What about the …