Documentation > Data > Data Preprocessing

Normalization & Standardization

Scaling transforms numerical features to a similar range, preventing features with larger values from dominating the model. Different scaling methods are appropriate for different algorithms and data distributions.

Scaling Options

Our form provides four scaling options for your numerical features:

Min-Max Scaling

Transforms features to a specific range (typically 0 to 1). Preserves the shape of the distribution while ensuring all features have the same scale.

Standard Scaling

Transforms features to have zero mean and unit variance. Best for algorithms that assume normally distributed data, like linear regression and neural networks.

Normalizer

Scales individual samples to have a unit norm (typically L1, L2, or max norm). Useful when the scale of each sample matters more than the feature distributions.

None

Skip scaling if your features are already on a similar scale or when using algorithms that are invariant to feature scaling (like tree-based methods).

Selecting a Scaling Method

To choose a scaling method in the form, simply click on one of the scaling option cards. The selected option will be highlighted with the primary color.

Selection Tips

  • For most cases, Min-Max Scaling or Standard Scaling works well
  • For algorithms sensitive to feature distributions, like SVMs or PCA, use Standard Scaling
  • For text data or when comparing document vectors, use Normalizer
  • For tree-based algorithms (Random Forest, XGBoost), you can select None

When to Use Each Method

Scaling MethodBest ForCompatible Algorithms
Min-Max Scaling
  • Data with outliers
  • Non-normal distributions
  • When a bounded range is needed
Neural networks, K-nearest neighbors, algorithms using distance metrics
Standard Scaling
  • Normally distributed data
  • Linear models
  • Feature importance analysis
Linear/logistic regression, SVMs, PCA, neural networks
Normalizer
  • Text data (TF-IDF vectors)
  • Sample-focused analysis
  • Cosine similarity calculations
Text classification, clustering, recommendation systems
None
  • Tree-based models
  • Already scaled data
  • Similar-range features
Decision trees, Random Forest, Gradient Boosting

How Each Scaling Method Works

Min-Max Scaling

Transforms features to a range of [0, 1] using the formula:

X_scaled = (X - X_min) / (X_max - X_min)

OriginalMin-Max Scaled
100.0
300.5
501.0

Standard Scaling

Transforms features to have zero mean and unit variance using the formula:

X_scaled = (X - X_mean) / X_std

OriginalStandard Scaled
10-1.22
300.0
501.22

Normalizer

Scales each sample (row) to have a unit norm. With L2 normalization, the formula is:

X_normalized = X / ||X||

(where ||X|| is the L2 norm of the sample)

This transforms each sample so that its Euclidean distance from the origin equals 1. Unlike the other methods, normalization operates on rows (samples) rather than columns (features).

Important Considerations

Scaling Implications

Outlier Sensitivity: Standard Scaling can be more sensitive to outliers than Min-Max Scaling. If your data contains extreme values, consider using robust scaling techniques or Min-Max Scaling.

Tree-Based Models: Decision trees, Random Forests, and other tree-based algorithms are invariant to feature scaling because they make decisions based on sorting values, not their magnitudes.

Data Leakage: Always fit your scaler on the training data only, then apply the same transformation to test data. This prevents information from the test set influencing the scaling parameters.

Interpretability: Scaling affects model coefficient magnitudes, which can impact the interpretation of feature importance in linear models. Consider this when analyzing your models.

New Data Points

When applying your model to new data, you must use the same scaling parameters (mean, standard deviation, min, max) from the training data. Our platform handles this automatically when you deploy your models.

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Last updated: 3/22/2025

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