Hands-On Q-Learning with Python

Extensional versus intensional definitions

An extensional definition is a definition that is given in examples, as opposed to an intensional or "dictionary" definition. An extensional definition of the word "car" might be various labeled images of cars, along with labeled images of objects that are not cars.

A neural network trained on these images should be able to identify new images that are not in the training set as belonging to either the "car" or "not car" class. Once it has accomplished this with a level of accuracy that is useful for the purposes we are putting it to, we can say that it has learned to define what a car is.

By contrast, an intensional definition of "car" might be "a four-wheeled vehicle powered by an internal combustion ...