To adapt in an ever-changing world, people infer what basic
units should be used to form concepts and guide generalizations.
While recent computational models of human representation
learning have successfully predicted how people discover
features from high-dimensional input in a number of domains
(Austerweil & Griffiths, 2013), the learned features are
assumed to be additive. However, this assumption is not always
true in the real world. Sometimes a basic unit is substitutive
(Garner, 1978), which means it can only be one value out
of a set of discrete values. For example, a cat is either furry
or hairless, but not both. In this paper, we explore how people
form representations for substitutive features, and what computational
principles guide such behavior. In a behavioral experiment,
we show that not only are people capable of forming
substitutive feature representations, but they also infer whether
a feature should be additive or substitutive depending on the
observed input. This learning behavior is predicted by our
novel extension to the Austerweil and Griffiths (2011, 2013)’s
feature construction framework, but not their original model.
Our work contributes to the continuing effort to understand
how people form representations of the world.