arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1302.6777cs.CL
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基于结尾的词性标注策略

Ending-based Strategies for Part-of-speech Tagging

University of Saskatchewan(萨斯喀彻温大学)

Greg Adams, Beth Millar, Eric Neufeld, Tim Philip

摘要:

词性标注的概率方法主要依赖于关于词/标签组合的全词统计以及上下文信息。但经验表明,即使训练集高达100万个单词,测试集中也有大约4%的标记是未知的。看不见的单词使用二级策略标记,这些策略利用单词的特征,如结尾,大写和标点符号。在这项工作中,词尾统计是主要的,全词统计是次要的。首先,一个标记者只接受了单词结尾的训练和测试。随后的实验为训练集中出现频率最高的单词添加了全词统计数据。随着规模的扩大,性能有望提高,在极限情况下,性能与基于单词的标记器相同。令人惊讶的是,基于结尾的标记器最初的表现几乎和基于单词的标记器一样好;在最好的情况下,它的性能显着超过了基于单词的标记器。最后,出乎意料的是,出现了负回报的影响-随着规模的扩大,业绩普遍改善,然后又下降。通过改变结尾长度和标签列表策略等因素,我们实现了97.5%的成功率。

英文摘要:

Probabilistic approaches to part-of-speech tagging rely primarily on whole-word statistics about word/tag combinations as well as contextual information. But experience shows about 4 per cent of tokens encountered in test sets are unknown even when the training set is as large as a million words. Unseen words are tagged using secondary strategies that exploit word features such as endings, capitalizations and punctuation marks. In this work, word-ending statistics are primary and whole-word statistics are secondary. First, a tagger was trained and tested on word endings only. Subsequent experiments added back whole-word statistics for the words occurring most frequently in the training set. As grew larger, performance was expected to improve, in the limit performing the same as word-based taggers. Surprisingly, the ending-based tagger initially performed nearly as well as the word-based tagger; in the best case, its performance significantly exceeded that of the word-based tagger. Lastly, and unexpectedly, an effect of negative returns was observed - as grew larger, performance generally improved and then declined. By varying factors such as ending length and tag-list strategy, we achieved a success rate of 97.5 percent.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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