| Abstract: |
Theories of human and machine learning have influenced each other for more than
fifty years, and the interaction between these fields continues to be
productive. I will discuss two probabilistic models that attempt to contribute
to both fields. Standard methods for unsupervised learning discover
representations of a single kind: for instance, algorithms for hierarchical
clustering can only discover tree structures, and algorithms for
dimensionality-reduction can only discover low-dimensional spaces. I will
present a hierarchical Bayesian framework that discovers for itself which kind
of representation is best for a given problem. Simple representations like
trees and low-dimensional spaces are useful in some contexts, but many aspects
of human knowledge demand richer relational representations. I will present a
nonparametric Bayesian method for discovering simple relational theories and
will show how it can be tested as a psychological model. |