Hiroki Ouchi

Nara Institute of Science and Technology | NAIST · Graduate School of Information Science

Avoiding the generation of responses that contradict the preceding context is a significant challenge in dialogue response generation. One feasible method is post-processing, such as filtering out contradicting responses from a resulting n-best response list. In this scenario, the quality of the n-best list considerably affects the occurrence of co...

Developing an automatic evaluation framework for open-domain dialogue response generation systems that can validate the effects of daily system improvements at a low cost is necessary. However, existing metrics commonly used for automatic response generation evaluation, such as bilingual evaluation understudy (BLEU), correlate poorly with human eva...

Interpretable rationales for model predictions are crucial in practical applications. We develop neural models that possess an interpretable inference process for dependency parsing. Our models adopt instance-based inference, where dependency edges are extracted and labeled by comparing them to edges in a training set. The training edges are explic...

Existing approaches for automated essay scoring and document representation learning typically rely on discourse parsers to incorporate discourse structure into text representation. However, the performance of parsers is not always adequate,especially when they are used on noisy texts, such as student essays. In this paper, we propose an unsupervis...

The use of pretrained masked language models (MLMs) has drastically improved the performance of zero anaphora resolution (ZAR). We further expand this approach with a novel pretraining task and finetuning method for Japanese ZAR. Our pretraining task aims to acquire anaphoric relational knowledge necessary for ZAR from a large-scale raw corpus. The...

Recent progress in language modeling is promoting research on a question answering (QA) task without reading comprehension, which is called closed-book QA. While previous studies are focused on enlarging and sophisticating a model to address this task, we take a data-oriented approach to teach a model about diverse factual knowledge efficiently. We...

Short Answer Grading (SAG) is the task of scoring students’ answers for applications such as examinations or e-learning. Most of the existing SAG systems predict scores based only on the answers, and critical evaluation criteria such as rubrics are ignored, which plays a crucial role in evaluating answers in real-world situations. In this paper, we...

Argumentation Structure Parsing (ASP) is the task of predicting the roles of argumentative units (e.g., claim, premise) and the relations between the units (e.g., support, attack) in an argumentative text. ASP has received a great deal of attention due to its usefulness for applications such as automatic assessment of argumentative texts. As textua...

One critical issue of zero anaphora resolution (ZAR) is the scarcity of labeled data. This study explores how effectively this problem can be alleviated by data augmentation. We adopt a state-of-the-art data augmentation method, called the contextual data augmentation (CDA), that generates labeled training instances using a pretrained language mode...

Existing approaches for automated essay scoring and document representation learning typically rely on discourse parsers to incorporate discourse structure into text representation. However, the performance of parsers is not always adequate, especially when they are used on noisy texts, such as student essays. In this paper, we propose an unsupervi...

In general, the labels used in sequence labeling consist of different types of elements. For example, IOB-format entity labels, such as B-Person and I-Person, can be decomposed into span (B and I) and type information (Person). However, while most sequence labeling models do not consider such label components, the shared components across labels, s...

Existing automatic evaluation metrics for open-domain dialogue response generation systems correlate poorly with human evaluation. We focus on evaluating response generation systems via response selection. To evaluate systems properly via response selection, we propose the method to construct response selection test sets with well-chosen false cand...

Interpretable rationales for model predictions play a critical role in practical applications. In this study, we develop models possessing interpretable inference process for structured prediction. Specifically, we present a method of instance-based learning that learns similarities between spans. At inference time, each span is assigned a class la...

We present a simple and accurate span-based model for semantic role labeling (SRL). Our model directly takes into account all possible argument spans and scores them for each label. At decoding time, we greedily select higher scoring labeled spans. One advantage of our model is to allow us to design and use span-level features, that are difficult t...

We present a simple and accurate span-based model for semantic role labeling (SRL). Our model directly takes into account all possible argument spans and scores them for each label. At decoding time, we greedily select higher scoring labeled spans. One advantage of our model is to allow us to design and use span-level features, that are difficult t...

Developing conversational systems that can converse in many languages is an interesting challenge for natural language processing. In this paper, we introduce multilingual addressee and response selection. In this task, a conversational system predicts an appropriate addressee and response for an input message in multiple languages. A key to develo...

Developing conversational systems that can converse in many languages is an interesting challenge for natural language processing. In this paper, we introduce multilingual addressee and response selection. In this task, a conversational system predicts an appropriate addressee and response for an input message in multiple languages. A key to develo...

To create conversational systems working in actual situations, it is crucial to assume that they interact with multiple agents. In this work, we tackle addressee and response selection for multi-party conversation, in which systems are expected to select whom they address as well as what they say. The key challenge of this task is to jointly model...

Lexical information, including surface word form and part-of-speech (POS) information, plays a crucial role when predicting ambiguous dependency relationships in dependency parsing. However, for resolving dependency ambiguities, surface word information may be too sparse, while POS information may be too coarse. Supertags, which are lexical templat...

Existing methods for Japanese predicate argument structure (PAS) analysis identify case arguments of each predicate without considering interactions between the target PAS and others in a sentence. However , the argument structures of the predicates in a sentence are semantically related to each other. This paper proposes new methods for Japanese P...