Standardization

Standardization puts numerical variables on the same scale. It centers each variable around its mean and scales it to unit variance. This makes values easier to compare and often improves machine learning model performance.

Example

Consider a dataset with students' test scores across subjects that use different grading scales. Those scale differences make it hard to compare performance across subjects or build a model that predicts overall performance well. Standardizing each variable by subtracting the mean and dividing by the standard deviation puts the inputs on a common scale, so the model can judge each subject more accurately and produce better predictions.