This thesis examines disfluencies (e.g., "um", repeated words, and a variety of forms of self-repair) in the spontaneous speech of adult normal speakers of American English. Despite their prevalence, disfluencies have traditionally been viewed as irregular events and have received little attention. The goal of the thesis is to provide evidence that, on the contrary, disfluencies show remarkably regular trends in a number of dimensions. These regularities have consequences for models of human language production; they can also be exploited to improve performance in speech applications. The method includes analysis of over 5000 hand-annotated disfluencies from a database (250,000 words) containing three different styles of spontaneous speech: task-oriented human-computer dialog, task-oriented human-human dialog, and human-human conversation on a prescribed topic. The approach is theory-neutral and strongly data-driven. The annotations correspond to observable characteristics ("features") ...

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Speakers often repeat the first word of major constituents, as in, ‘‘I uh I wouldn’t be surprised at that.’ ’ Repeats like this divide into four stages: an initial commitment to the constituent (with ‘‘I’’); the suspension of speech; a hiatus in speaking (filled with ‘‘uh’’); and a restart of the constituent (‘‘I wouldn’t...’’). An analysis of all repeated articles and pronouns in two large corpora of spontaneous speech shows that the four stages reflect different principles. Speakers are more likely to make a premature commitment, immediately suspending their speech, as both the local constituent and the constituent containing it become more complex. They plan some of these suspensions from the start as preliminary commitments to what they are about to say. And they are more likely to restart a constituent the more their stopping has disrupted its delivery. We argue that the principles governing these stages are general and not specific to repeats.

In the literature dealing with the reanalysis of garden path sentences such as While the man hunted the deer ran into the woods, it is generally assumed that people either completely repair their initial incorrect syntactic representations yielding a final interpretation whose syntactic structure is fully consistent with the input string, or that the parse fails. In a series of five experiments, we explored the possibility that partial reanalyses take place. Specifically, we examined the conditions under which part of the initial incorrect analysis persists at the same time that part of the correct final analysis is constructed. In Experiments 1a and 1b, we found that both the length of the ambiguous region and the plausibility of the ultimate interpretation affected the likelihood that such sentences would be fully reanalyzed. In Experiment 2, we compared garden path sentences with non-garden path sentences and compared performance on two different types of comprehension questions. In...

Variations in postverbal constituent ordering have been attributed to both grammatical complexity (heaviness) and discourse status (newness), although few studies compare the two factors explicitly. Through corpus analysis and experimentation, we demonstrate that both factors simultaneously and independently influence word order in two English constructions. While past investigations of these factors have focused on their effects in language comprehension, we argue that postponing heavy and new constituents facilitates processes of planning and production.* Even relatively fixed-word-order languages like English permit certain phrases to occur in more than one order. Examples 1–3 illustrate three familiar alternations in the sequencing of postverbal constituents. (1) Heavy NP Shift 1 (HNPS) a. The waiter brought the wine we had ordered to the table. b. The waiter brought to the table the wine we had ordered. (2) Dative Alternation (DA) a. Chris gave a bowl of Mom’s traditional cranberry sauce to Terry. b. Chris gave Terry a bowl of Mom’s traditional cranberry sauce.

To understand a sentence, the meanings of the words in the sentence must be retrieved and combined. Are these meanings represented within the language system (the lexical hypothesis) or are they represented in a general conceptual system that is not restricted to language (the conceptual hypothesis)? To evaluate these hypotheses, sentences were presented in which a pictured object replaced a word (rebus sentences). Previous research has shown that isolated pictures and words are processed equally rapidly in conceptual tasks, but that pictures are markedly slower than words in tasks requiring lexical access. The lexical hypothesis would therefore lead one to expect that rebus sentences will be relatively difficult, whereas the conceptual hypothesis would predict that rebus sentences would be rather easy. Sentences were shown using rapid serial visual presentation (RSVP) at a rate of 10 or 12 words per second. With one set of materials (Experiments 1 and 2), readers took longer to judge the plausibility of rebus sentences than all-word sentences, although the accuracy of judgment and of recall were similar for the two formats. With two new sets of materials (Experiments 3 and 5), rebus and all-word sentences were virtually equivalent except in

ing away from irrelevant details is a theoretical virtue, but the kinds of abstractions that module geography makes can lead to incorrect inferences from data. That such a possibility exists is clearly demonstrated by the working memory research of Just & Carpenter (1992). Briefly, Just and Carpenter have argued that some garden path effects that were previously interpreted in terms of a syntactically encapsulated module can instead be explained by individual differences in working memory capacity. Such an explanation is not considered in a theoretical framework that systematically ignores the role of memory structures in parsing. This point should be taken regardless of whether one is convinced by the current body of empirical support for this particular model---the fact remains that such an explanation could in principle account for the data, and these alternative explanations are only discovered by developing functionally complete architectures. The next few sections describes what ...

Guided by interpersonal deception theory and the principle of interactivity, this investigation examined whether communication modalities differentially affect the extent to which group members develop trust or are vulnerable to manipulation and deceit, based on the degree of interactivity the modalities afford. According to the principle of interactivity, involvement and mutuality should increase as one moves from text, to audio and audiovisual (AV) modalities, to face-to-face (FtF) communication. Under nondeceptive circumstances, greater interactivity should elicit corresponding increases in trust and credibility; under deceptive circumstances, it should produce greater truth biases and inaccurate detection of deceit. This effect should be partly mitigated in text and audio modalities due to the presence of diagnostic deception indicators Pairs were assigned to a truthful or deceptive condition in one of three mediated conditions, or in a face-to-face condition. In the deceptive condition, one member of each pair was enlisted to deceive during the interaction. Following discussion, participants rated their communicative behavior and the credibility of the truthful or deceptive actor. Truth bias and accuracy in judging deceptive information was calculated. Results are compared to previous findings from face-to-face deception. Implications for collaborative technologies are advanced.

To learn a language, the learners must first learn its words, the essential building blocks for utterances. The difficulty in learning words lies in the unavailability of explicit word boundaries in speech input. The learners have to infer lexical items with some innately endowed learning mechanism(s) for regularity detection- regularities in the speech normally indicate word patterns. With respect to Zipf's least-effort principle and Chomsky's thoughts on the minimality of grammar for human language, we hypothesise a cognitive mechanism underlying language learning that seeks for the least-effort representation for input data. Accordingly, lexical learning is to infer the minimal-cost representation for the input under the constraint of permissible representation for lexical items. The main theme of this thesis is to examine how far this learning mechanism can go in unsupervised lexical learning from real language data without any pre-defined (e.g., prosodic and phonotactic) cues, but entirely resting on statistical induction of structural patterns for the most economic representation for the data. We first review

Automated Directory Assistance (ADA) allows users to request telephone or address information of residential and business listings using speech recognition. Because callers often express listings differently than how they are registered in the directory, ADA systems require transcriptions of alternative phrasings for directory listings as training data, which can be costly to acquire. As such, a framework in which data can be contributed voluntarily by large numbers of Internet users has tremendous value. In this paper, we introduce People Watcher, a computer game that elicits transcribed, alternative user phrasings for directory listings while at the same time entertaining players. Data generated from the game not only overlapped actual audio transcriptions, but resulted in a statistically significant 15% relative reduction in semantic error rate when utilized for ADA. Furthermore, semantic accuracy was not statistically different than using the actual audio transcriptions. Index Terms: game, automated directory assistance 1.