Exact Hard Monotonic Attention for Character-Level Transduction

Fuente: arXiv
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Main Authors: Wu, Shijie, Cotterell, Ryan
Format: Preprint
Published: 2019
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author Wu, Shijie
Cotterell, Ryan
author_facet Wu, Shijie
Cotterell, Ryan
contents Many common character-level, string-to string transduction tasks, e.g., grapheme-tophoneme conversion and morphological inflection, consist almost exclusively of monotonic transductions. However, neural sequence-to sequence models that use non-monotonic soft attention often outperform popular monotonic models. In this work, we ask the following question: Is monotonicity really a helpful inductive bias for these tasks? We develop a hard attention sequence-to-sequence model that enforces strict monotonicity and learns a latent alignment jointly while learning to transduce. With the help of dynamic programming, we are able to compute the exact marginalization over all monotonic alignments. Our models achieve state-of-the-art performance on morphological inflection. Furthermore, we find strong performance on two other character-level transduction tasks. Code is available at https://github.com/shijie-wu/neural-transducer.
format Preprint
id arxiv_https___arxiv_org_abs_1905_06319
institution arXiv
publishDate 2019
record_format arxiv
spellingShingle Exact Hard Monotonic Attention for Character-Level Transduction
Wu, Shijie
Cotterell, Ryan
Computation and Language
Many common character-level, string-to string transduction tasks, e.g., grapheme-tophoneme conversion and morphological inflection, consist almost exclusively of monotonic transductions. However, neural sequence-to sequence models that use non-monotonic soft attention often outperform popular monotonic models. In this work, we ask the following question: Is monotonicity really a helpful inductive bias for these tasks? We develop a hard attention sequence-to-sequence model that enforces strict monotonicity and learns a latent alignment jointly while learning to transduce. With the help of dynamic programming, we are able to compute the exact marginalization over all monotonic alignments. Our models achieve state-of-the-art performance on morphological inflection. Furthermore, we find strong performance on two other character-level transduction tasks. Code is available at https://github.com/shijie-wu/neural-transducer.
title Exact Hard Monotonic Attention for Character-Level Transduction
topic Computation and Language
url https://arxiv.org/abs/1905.06319