Qu’est-ce que la régularisation et comment empêche-t-elle le surapprentissage ?

As of my knowledge, regularization is a method in machine Learning to prevent data from overfitting by adding constraints or penalties to the model's loss function. It helps to discourage the use of complex and intricate patterns that may fit the training data too closely. - This helps the model generalize better to new, unseen data by promoting simpler and more robust patterns, ultimately improving its performance on unseen datasets. - Common regularization methods are L1 regularization (Lasso) and L2 regularization (Ridge).

Regularization is a method used to prevent overfitting in models by introducing additional information or constraints. It's widely applied not just in machine learning but also in inverse problems like tomography. Regularization typically works by penalizing the complexity of the model to ensure better generalization and stability. Complexity means how flexible the model is in fitting the data. A more complex model can fit the training data very closely but also capture noise or random fluctuations. Regularization addresses this by imposing a complexity cost, promoting better robustness and stability of the solution.

Regularization is a technique used in machine learning to prevent over fitting. It is used to make the model less complex, which will prevent it from memorising the train dataset.

Regularization in machine learning helps stop models from getting too complex and overfitting by adding a penalty for complexity. It stops them from fitting too much to the training data's noise, so they're better at understanding new data. Techniques like Ridge, Lasso, and Elastic Net add these penalties to the model's building blocks, keeping them from growing too big and keeping things simpler.

Let me add my view in two ways 1. Simple understanding --> We prepared some food, before it gets finish we generally taste and check whether its okay or missing or something which is messy. To get our food right, will add some ingredients to make it tasty it could either water (to reduce salty) or add some spicy ingredients. 2. Likewise, will talk more in technical prospect Regularization is a method of dealing overfitting or complex training. Techniques like (water from above example) Ridge, Lasso and Elastic to keep our model gets simple.

Regularization penalizes the weights/coefficients of a model and prevents them from growing too large. If the weights/coefficients are too large, a slight change in any of the inputs may result in a huge variance in the model's prediction, thereby resulting in a model with huge variance.

The various types of regularization apply penalties to the model weights/parameters to avoid the growth of these weights to very large values. The model with very large weights will consider noise and insignificant details in the training data. The model with appropriate weights considers the significant patterns while ignoring the noise and insignificant details in the training data. This model weight regularization controls the sensitivity of the model to promote learning and prevent memorization, which enhances the model generalization.

Elastic net regression combines both Lasso (L1) and Ridge (L2) regularizations using a mixing parameter to achieve balance between L1 and L2 regularizations.

1. Understand: Consider your model complexity and data size. Complex models & limited data benefit more. 2. Choose: L1 for sparsity and interpretability, L2 for general shrinkage, or Elastic Net for a balance. Dropout works well for neural networks. 3. Tune: Use grid search, random search, or early stopping on a validation set to find the best parameter strength. 4. Evaluate and iterate: Monitor training and validation errors to adjust the regularization strength or model complexity. Remember, it's an iterative process! Don't be afraid to experiment and find the best fit for your specific case.

Regularization in machine learning is not a one-size-fits-all solution; it's a set of techniques aimed at preventing overfitting by adding a penalty term to the model's objective function. The specific regularization method or technique to be used depends on various factors, including type of data, model complexity, volume of dataset, features, and domain-specific knowledge. Choosing the right method involves experimentation, validation, and understanding the trade-offs between bias and variance in the model. The adaptive selection of regularization methods based on these considerations is crucial for effective model training, as there is no one definitive formula or method applicable to all scenarios in machine learning.

In practical practices, it is a good idea to experiment with various regularization techniques and strengths, evaluate their effectiveness using cross-validation, and select the regularization strategy that produces the best outcomes for your particular situation. Regularization is a type of hyperparameter tweaking, and depending on the situation, several options may be best.

On the training set, we estimate several different Ridge regressions, with different values of the regularization parameter; on the validation set, we choose the best model . the regularization parameter which gives the lowest MSE on the validation set. Another factor is the dataset size and features importance , if we aim to do feature selection along with regularization may be we use L1 to exclude and add zero weights to unnecessary features.

When I use regularization in my Project, I experiment with different techniques like Ridge, Lasso, or Elastic Net. I tweak their settings, like the strength of the penalty, to find the best fit for my model. It's like adjusting a dial to get the right balance between simplicity and accuracy in the predictions. After trying out these methods, I choose the one that works best for the specific problem I'm working on.

To sum-up: It's all about the right tools and techniques. In scikit-learn, try Lasso/Ridge for L1/L2 in linear models. TensorFlow/Keras? Check out the regularizers module. PyTorch fan? weight_decay for L2 or nn.Dropout for layer-wise control.