2016/09/15 by Nitish Shirish Keskar, Dheevatsa Mudigere, Keskar, Nitish Shirish +7 · 185 citations
Computer Science · #Stochastic Gradient Optimization Techniques #Machine Learning and Algorithms #Machine Learning and ELM
paper · pdf · doi:10.48550/arxiv.1609.04836
The stochastic gradient descent (SGD) method and its variants are algorithms\nof choice for many Deep Learning tasks. These methods operate in a small-batch\nregime wherein a fraction of the training data, say 32-512 data points, is\nsampled to compute an approximation to the gradient. It has been observed in\npractice that when using a larger batch there is a degradation in the quality\nof the model, as measured by its ability to generalize. We investigate the\ncause for this generalization drop in the large-batch regime and present\nnumerical evidence that supports the view that large-batch methods tend to\nconverge to sharp minimizers of the training and testing functions - and as is\nwell known, sharp minima lead to poorer generalization. In contrast,\nsmall-batch methods consistently converge to flat minimizers, and our\nexperiments support a commonly held view that this is due to the inherent noise\nin the gradient estimation. We discuss several strategies to attempt to help\nlarge-batch methods eliminate this generalization gap.\n