Learning Switching Concepts

We consider learning in situations where the function used to classify examples may switch back and forth between a small number of different concepts during the course of learning. We examine several models for such situations: oblivious models in which switches are made independent of the selection of examples, and more adversarial models in which a single adversary controls both the concept switches and example selection. We show relationships between the more benign models and the pconcepts of Kearns and Schapire, and present polynomial-time algorithms for learning switches between two k-DNF formulas. For the most adversarial model, we present a model of success patterned after the popular competitive analysis used in studying on-line algorithms. We describe a randomized query algorithm for such adversarial switches between two monotone disjunctions that is "l-competitive" in that the total number of mistakes plus queries is with high probability bounded by the number of...

• Type: Conference
• Year: 1992
• Where: COLT
• Authors: Avrim Blum, Prasad Chalasani
• Keywords: Adversarial Model, Adversarial Switches, COLT 1992, Concept Switches, Machine Learning