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Weight decay

As explained in Machine Learning Algorithms in Depth

A regularization method that adds a penalty proportional to the squared magnitude of model parameters to discourage large weights.

Weight decay is a regularization method that penalizes the squared magnitude of model parameters, discouraging large weights and promoting simpler models. In multilayer perceptrons, apply it to nonbias weights W rather than bias parameters b to help prevent overfitting. section 10.1

Use weight decay as one option within a broader regularization strategy:

  • Increase model capacity with additional layers or hidden units when the model underfits. section 10.1
  • Prefer weight decay when overfitting calls for smaller weights and simpler models. section 10.1
  • Contrast it with early stopping, which halts training as validation loss rises, and dropout, which randomly removes dense connections. section 10.1

How Machine Learning Algorithms in Depth covers it

How deep it goes
Defines the penalty’s purpose and parameter scope but stops short of deriving its update rule or implementation details.
Examples
Applies the penalty to nonbias weights W rather than biases b in each multilayer perceptron layer.
What you can do after
Apply it to nonbias weights when training a multilayer perceptron to discourage overfitting.
How it connects
Connects weight decay with regularization, overfitting, model capacity, early stopping, dropout, and multilayer perceptrons.

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This explainer was generated by Manning's knowledge graph from the text of Machine Learning Algorithms in Depth. The section links point to the parts of the book it draws on.