Sobreparametrização refere-se a uma situação em aprendizado de máquina where a model has more parameters than the amount of data available for training. This can lead to a model that fits the dados de treinamento extremely well, potentially capturing noise rather than the underlying structure of the data. While it may seem counterintuitive, overparameterization is common in aprendizado profundo, where models can have millions of parameters.
In many cases, overparameterized models can generalize well despite their complexity. This is due to the ability of these models to learn intricate patterns from the data, which can lead to better performance on unseen data. However, it also increases the risk of overfitting, where the model memorizes the training data instead of learning to generalize from it.
To mitigate the risks associated with overparameterization, techniques such as regularization can be employed. Regularization methods, like L1 or Regularização L2, add a penalty for larger weights, encouraging simpler models that are less likely to overfit. Additionally, practices such as cross-validation help in avaliando o desempenho do modelo e evita o overfitting.
Em resumo, embora a sobreparametrização possa levar a modelos poderosos, ela exige um manuseio cuidadoso para garantir que o modelo se generalize bem para novos dados não vistos.