In a controlled experiment of sequence-to-sequence approaches for the task of
sentence correction, we find that character-based models are generally more
effective than word-based models and models that encode subword information via
convolutions, and that modeling the output data as a series of diffs improves
effectiveness over standard approaches. Our strongest sequence-to-sequence
model improves over our strongest phrase-based statistical machine translation
model, with access to the same data, by 6 M2 (0.5 GLEU) points. Additionally,
in the data environment of the standard CoNLL-2014 setup, we demonstrate that
modeling (and tuning against) diffs yields similar or better M2 scores with
simpler models and/or significantly less data than previous
sequence-to-sequence approaches.

对序列到序列方法进行的纠错实验中发现，基于字符的模型通常比基于单词的模型和通过卷积编码子单词信息的模型更有效，并且将输出数据建模为一系列差异可提高效果，而我们最强的序列到序列模型比最强的基于短语的统计机器翻译模型在数据相同的情况下得分提高了 6 M2 点（0.5 GLEU）。此外，在标准 CoNLL-2014 设置的数据环境中，我们证明了建模（并调整）差异可以使用更简单的模型和 / 或比以前的序列到序列方法少得多的数据获得类似或更好的 M2 得分。