Standard Scaling Method

What is Standard Scaling?

Standard Scaling (also called Z-score normalization) is a data preprocessing technique that transforms features to have a mean of 0 and a standard deviation of 1.

Formula

z = (x - mean) / std

Where:
- z: Scaled value
- x: Original value
- mean: Mean of the feature
- std: Standard deviation of the feature

When to Use It

  • Algorithms sensitive to scale: SVM, KNN, neural networks
  • Gradient-based algorithms: Logistic regression, neural networks
  • Distance-based methods: K-means clustering

When NOT to Use It

  • Tree-based algorithms: Random Forest, XGBoost (scale-invariant)
  • When interpretability matters: Scaled values are harder to interpret

Related Methods

  • MinMax Scaling: Scales to a fixed range (0-1)
  • Robust Scaling: Uses median and quartiles (handles outliers)

Related Terms

  • Random Forest: Scale-invariant algorithm