Understanding the Mechanics of SPIGOT: Surrogate Gradients for Latent Structure Learning

التفاصيل البيبلوغرافية
العنوان: Understanding the Mechanics of SPIGOT: Surrogate Gradients for Latent Structure Learning
المؤلفون: Mihaylova, Tsvetomila, Niculae, Vlad, Martins, André F. T.
سنة النشر: 2020
المجموعة: Computer Science
مصطلحات موضوعية: Computer Science - Computation and Language, Computer Science - Machine Learning
الوصف: Latent structure models are a powerful tool for modeling language data: they can mitigate the error propagation and annotation bottleneck in pipeline systems, while simultaneously uncovering linguistic insights about the data. One challenge with end-to-end training of these models is the argmax operation, which has null gradient. In this paper, we focus on surrogate gradients, a popular strategy to deal with this problem. We explore latent structure learning through the angle of pulling back the downstream learning objective. In this paradigm, we discover a principled motivation for both the straight-through estimator (STE) as well as the recently-proposed SPIGOT - a variant of STE for structured models. Our perspective leads to new algorithms in the same family. We empirically compare the known and the novel pulled-back estimators against the popular alternatives, yielding new insight for practitioners and revealing intriguing failure cases.
Comment: EMNLP 2020
نوع الوثيقة: Working Paper
URL الوصول: http://arxiv.org/abs/2010.02357
رقم الأكسشن: edsarx.2010.02357
قاعدة البيانات: arXiv