MSPA-MCS: collaborative research: Statistical Learning Methods for Complex Decision Problems in Natural Language Processing

在自然语言处理应用中出现的模式分类问题，例如解析，机器翻译和语音识别，比通常使用统计学习方法解决的问题更复杂。 该研究项目的主要目标是设计和分析适用于这些问题的统计学习算法。 本文针对自然语言处理中复杂模式分类问题的特点，研究了以下几个问题：具有理想统计和计算特性的多类分类方法;预测变量来自具有丰富结构的大集合的结构化分类方法（例如，预测句子的分析树）;这些方法的扩展到隐变量问题，即，一些相关数据未被观察到;和复杂的非参数模型，这些问题，特别是，计算效率高的非参数贝叶斯方法的基础上分层狄利克雷过程。 开发的方法将在解析，机器翻译和语音识别问题上进行经验验证。该研究项目旨在开发和分析用于复杂决策问题的统计学习方法，例如自然语言处理中出现的问题。 自然语言处理研究的一个关键目标是开发自动化系统，如翻译系统和对话系统。 最成功的方法涉及使用统计方法来利用语言数据，如文本语料库。 然而，由此产生的决策问题非常复杂。 一个很好的例子是解析问题，或者恢复语言中句子的句法结构。 对于这样的问题，候选决策集是非常大的，并具有相当大的结构。 该研究项目旨在开发适用于此类复杂决策问题的计算和统计方法。 成功的方法也可能对计算机科学的其他领域产生重大影响，包括计算机视觉和生物信息学，因为这些领域也会出现类似的复杂决策问题。

Pattern classification problems that arise in natural language processing applications, such as parsing, machine translation, and speech recognition, are more complex than those commonly addressed with statistical learning methods. The broad goal of this research project is the design and analysis of statistical learning algorithms that are suitable for these problems. The research is focused on the following questions, which are motivated by characteristic properties of complex pattern classification problems in natural language processing: methods for multiclass classification with desirable statistical and computational properties; methods for structured classification, where the predicted variables come from a large set with a rich structure (for example, predicting the parse tree of a sentence); the extension of these methods to problems with hidden variables, that is, where some relevant data is not observed; and complex nonparametric models for these problems, in particular, computationally efficient nonparametric Bayesian methods based on hierarchical Dirichlet processes. The methods developed will be validated empirically on parsing, machine translation, and speech recognition problems.The research project is aimed at the development and analysis of statistical learning methods for complex decision problems, such as those that arise in natural language processing. A key goal of research in natural language processing is the development of automated systems, such as translation systems and dialogue systems. The most successful approaches involve the use of statistical methods to exploit language data, such as a text corpus. However, the decision problems that arise are very complex. A good example is the problem of parsing, or recovering the syntactic structure underlying sentences in a language. For such problems, the set of candidate decisions is very large, and possesses considerable structure. This research project is aimed at developing computational and statistical methods that are suitable for complex decision problems of this kind. Successful methods are also likely to have a significant impact in other areas of computer science, including computer vision and bioinformatics, because similar complex decision problems also arise in these areas.