Information Gain

/ˌɪn.fərˈmeɪ.ʃən ɡeɪn/

noun … “measuring how much a split enlightens.”

Information Gain is a metric used in decision tree learning and other machine learning algorithms to quantify the reduction in uncertainty (entropy) about a target variable after observing a feature. It measures how much knowing the value of a specific predictor improves the prediction of the outcome, guiding the selection of the most informative features when constructing decision trees, such as Decision Trees.

Ordinary Least Squares

/ˈɔːr.dən.er.i liːst skwɛərz/

noun … “fitting a line to tame the scatter.”

Ordinary Least Squares (OLS) is a fundamental method in statistics and regression analysis used to estimate the parameters of a linear model by minimizing the sum of squared differences between observed outcomes and predicted values. It provides the best linear unbiased estimates under classical assumptions, allowing analysts to quantify relationships between predictor variables and a response variable while assessing the strength and direction of these relationships.