Machine learning glossary and quick reference.

Cost Function – expresses the error between predicted and actual outcomes. In supervised machine learning, minimizing the cost will increase the accuracy with which the model correlates to the system described in the training data.

K-Nearest Neighbors (k-NN) algorithm – expects similar things to exist near each other (i.e. “Birds of a feather flock together”). k-NN is a supervised learning algorithm that can be used to solve both classification and regression problems.