Meta-Learning Adaptive Loss Functions
This addresses a key limitation in meta-learning for loss functions, offering incremental improvements for machine learning practitioners by enhancing training dynamics and final model performance.
The paper tackles the problem of offline loss function learning, which biases towards early training performance, by proposing an online adaptive loss function update method. The results show consistent outperformance over cross-entropy and offline techniques across various architectures and datasets.
Loss function learning is a new meta-learning paradigm that aims to automate the essential task of designing a loss function for a machine learning model. Existing techniques for loss function learning have shown promising results, often improving a model's training dynamics and final inference performance. However, a significant limitation of these techniques is that the loss functions are meta-learned in an offline fashion, where the meta-objective only considers the very first few steps of training, which is a significantly shorter time horizon than the one typically used for training deep neural networks. This causes significant bias towards loss functions that perform well at the very start of training but perform poorly at the end of training. To address this issue we propose a new loss function learning technique for adaptively updating the loss function online after each update to the base model parameters. The experimental results show that our proposed method consistently outperforms the cross-entropy loss and offline loss function learning techniques on a diverse range of neural network architectures and datasets.