伝 康晴

本研究では,日本語多人数会話における視線行動を分析し,視線と話者交替との関係を明らかにする.とくに,次話者が自己選択するケースに焦点をあて,i)話し手の視線の向け先である聞き手が次話者になるのか,ii)視線の向け先以外の聞き手が次話者になる場合があるとしたら,いかにしてそのようなことが起こるのかを明らかにする.視線方向が付与された3人会話データ12組を定量的・定性的に分析した結果,i)隣接ペアが用いられない場合でも,話し手に視線を向けられていた聞き手が次話者として自己選択しやすいという一般的傾向があることがわかった.さらに,ii)この傾向に反して視線の向け先以外の聞き手が次話者になるのは,a)視線を向けられていた聞き手が次発話を回避したり,期待された反応や連鎖上適切な発話を行わなかったりするとか,b)話題に関する知識や同意/不同意といったスタンスの共有の点から話し手と同じカテゴリーに属しているといった条件が必要であることがわかった.これらの結果は,話し手の視線の向け先が次話者になることへの優先性を示している.

In this paper, we propose a new annotation scheme for Japanese response tokens (RTs), which is based on strict and consistent procedures. Our scheme consists of two-stage annotation, in which RTs are first identified and classified according to their forms and then further sub-classified based on their sequential positions. Six forms are included in our class of RTs: i) responsive interjections, ii) expressive interjections, iii) lexical reactive expressions, iv) repetitions, v) completions, and vi) assessments. Some of them bear an additional tag according to their sequential position in the discourse: i) first pair parts, ii) second pair parts, iii) sequence-closing thirds, iv) other responding turns, and v) unclassifiable positions. We apply our scheme to annotate a Japanese three-party conversation corpus, and present the results of a preliminary analysis on the distribution of RTs in the corpus. © 2011 IEEE.

Speech disfluency has lately attracted considerable attention in the study of spontaneous speech. In one tradition, disfluencies are treated as the outcome of cognitive processes that run purely inside the speaker. In a second tradition, they are viewed as the result of certain strategies by which the speaker can have an effect on the addressees. This paper reviews our recent studies on disfluencies in Japanese spontaneous speech, putting particular emphasis on their functions in speech communication. Three studies, on word repetitions, fillers, and prolongation, are described in detail and discussed from the viewpoint of communicative strategies.

In this paper, we discuss lemma identification in Japanese morphological analysis, which is crucial for a proper formulation of morphological analysis that benefits not only NLP researchers but also corpus linguists. Since Japanese words often have variation in orthography and the vocabulary of Japanese consists of words of several different origins, it sometimes happens that more than one writing form corresponds to the same lemma and that a single writing form corresponds to two or more lemmas with different readings and/or meanings. The mapping from a writing form onto a lemma is important in linguistic analysis of corpora. The current study focuses on disambiguation of heteronyms, words with the same writing form but with different word forms. To resolve heteronym ambiguity, we make use of goshu information, the classification of words based on their origin. Founded on the fact that words of some goshu classes are more likely to combine into compound words than words of other classes, we employ a statistical model based on CRFs using goshu information. Experimental results show that the use of goshu information considerably improves the performance of heteronym disambiguation and lemma identification, suggesting that goshu information solves the lemma identification task very effectively.

In Japanese, the syntactic structure of a sentence is generally represented by the relationship between phrasal units, bunsetsus in Japanese, based on a dependency grammar. In many cases, the syntactic structure of a bunsetsu is not considered in syntactic structure annotation. This paper gives the criteria and definitions of dependency relationships between words in a bunsetsu and their applications. The target corpus for the word-level dependency annotation is a large spontaneous Japanese-speech corpus, the Corpus of Spontaneous Japanese (CSJ). One application of word-level dependency relationships is to find basic units for constructing accent phrases.

We examined whether filled pauses (FPs) affect listeners' predictions about the complexity of upcoming phrases in Japanese. Studies of spontaneous speech corpora show that constituents tend to be longer or more complex when they are immediately preceded by FPs than when they are not. From this finding, we hypothesized that FPs cause listeners to expect that the speaker is going to refer to something that is likely to be expressed by a relatively long or complex constituent. In the experiments, participants listened to sentences describing both simple and compound shapes on a computer screen. Their task was to press a button as soon as they had identified the shape corresponding to the description. Phrases describing shapes were immediately preceded by a FP, a silent pause of the same duration, or no pause. We predicted that listeners' response times to compound shapes would be shorter when there is a FP before phrases describing the shape than when there is no FP, because FPs are good cues to complex phrases, whereas response times to simple shapes would not be shorter with a preceding FP than without. The results of native Japanese and proficient non-native Chinese listeners agreed with the prediction and provided evidence to support the hypothesis. Response times of the least proficient non-native listeners were not affected by the existence of FPs, suggesting that the effects of FPs on non-native listeners depend on their language proficiency. (C) 2007 Elsevier B.V. All rights reserved.

千葉大学国立国語研究所国立国語研究所京都高度技術研究所東京大学情報通信研究機構国立国語研究所コーパス日本語学への応用を指向した形態素解析用電子化辞書UniDicを開発した。大規模コーパスに対する形態論情報付与作業には,計算機を用いた形態素解析システムの利用が不可欠であるが,既存の形態素解析システム用辞書には,コーパス日本語学への応用を考える上でさまざまな不都合がある。1つは,単位の認定がある場合には長く,ある場合には短いといった不揃いがあることであり,もう1つは,異表記や異形態に対して同一の見出しが与えられないということである。言語研究で重要な要件となる,このような単位の斉一性や見出しの同一性への対処といったことを中心に,本電子化辞書の設計方針とそれを実装した辞書データベースシステムについて述べる。さらに,この設計の有用性を示すため,表記や語形の変異に関するコーパス分析の事例を紹介する。

自発発話において,直前にフィラーのある,句や節などの主要構成素は,そうでない主要構成素に比べ,長い傾向がある。そのような傾向を聴き手が経験的に把握し,フィラーを,後続句の長さや内容の複雑さを予測する手掛かりとして用いているかどうかを,句境界のフィラー,「エート」について調べた。「エート」の後続句が指し示す対象を聴き手が同定するのにかかる時間は,「エート」がない場合と比べ,後続句が長い場合のみ短く,後続句が短く単純な場合は有意差がなかった。この結果から,句境界の「エート」は聴き手にとって,後続句の長さ,内容の複雑さを知る上での手掛かりとなっていることが示唆された。

This article describes the CallHome Japanese (CHJ) corpus and a project for annotating this corpus with various sorts of linguistic tags. The CHJ corpus is a collection of digitized speech data and text transcriptions of 120 spontaneous, unscripted telephone conversations. The annotation of the corpus provides word segmentations, part-of-speech tags and alignment with the speech for all words, semantic classes for nouns and verbs, and argument structures for verbs. A large scale, high quality corpus of naturally occurring conversations with such extensive linguistic annotations will provide a basis for scientific and technological investigation into human speech communication.

In this study, we investigate syntactic and prosodic features of the speaker's speech at points where turn-taking and backchannels occur, on the basis of our analysis of Japanese spontaneous dialogs. Specifically, we focus on features such as part of speech, duration, F0 contour pattern, relative height of the peak F0, energy trajectory pattern, and relative height of the peak energy at the final part of speech segments. We examine, first, the relationship between turn-taking/backchannels and each feature of speech segments independently, showing that the features examined in this study are all related to turn-taking or backchannels and that the way they correlate is fairly consistent with previous studies. Next, we explore the inter-relationship among the features with respect to turn-taking and backchannels. We show that in both turn-taking and backchannels, (1) some instances of syntactic features make extremely strong contributions, and (2) in general, syntax has a stronger contribution than any individual prosodic feature, although the whole prosody contributes as strongly as, or even more strongly than, syntax. We also discuss some implications of our results, comparing them with previous models that have mentioned roles of syntax and prosody in turn-taking and backchannels.

This paper proposes a new model for human sentence processing which makes use of predictability of verbs from nouns for ambiguity resolution. The main claim is that verb distribution given a subject noun and an object noun varies depending on the animacy of the object noun, and that this variance influences the GP effect in Japanese. First, we report experimental results showing the asymmetry for the object-animacy in the GP effect, which cannot be explained in terms of semantic fitness, that is essential in constraint-based models. Then, we show, on the basis of a corpus analysis, that the difference of the object-animacy is related not to semantic fitness between nouns and verbs but to predictability of verbs from nouns. Finally, we propose our model of disambiguation using verb-predictability, and, based on this model, explain the asymmetry for the object-animacy observed in our experiment.

Naturalness of expressions reflects various pragmatic factors in addition to grammatical factors. In this paper, we discuss relations between expressions and two pragmatic factors: a point of view of speaker and a hierarchical relation among participants. Degree of ''empathy'' and ''class'' is used to express these pragmatic factors as one-dimensional notion. Then inequalities and equalities of them become conditions for selecting natural expressions. The authors of this paper formulate conditions as principles about lexical and syntactical constraints, and have implemented a sentence generation grammar using the unification grammar formalism.