What Are the Disadvantages of L2 Regularization in Machine Learning?

Discover the main disadvantage of L2 regularization, including its impact on model interpretability and feature selection.

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L2 regularization's disadvantage is that it can lead to a model that is hard to interpret. By shrinking coefficients closer to zero, but not exactly zero, it does not perform feature selection as effectively as L1 regularization. This means that it keeps all features in the model, potentially including those that are irrelevant or redundant.

FAQs & Answers

  1. What is the difference between L1 and L2 regularization? L1 regularization can perform feature selection by shrinking some coefficients exactly to zero, effectively removing irrelevant features. In contrast, L2 regularization shrinks coefficients toward zero but rarely makes them exactly zero, retaining all features in the model.
  2. Why does L2 regularization make models harder to interpret? Because L2 regularization keeps all features with small but nonzero coefficients, it becomes difficult to identify which features are truly important, reducing the model's interpretability.
  3. When should I use L2 regularization over L1? L2 regularization is preferred when you want to prevent overfitting but still keep all features in the model, especially when the goal is to maintain stability and avoid abrupt feature elimination that L1 causes.