Publications

Abstract

The classification of texts and pieces of texts uses the occurrence of, combinations of, words as an important indicator. Not every word or each combination of words gives a clear indication of the classification of a piece of text. Research has been done on methods that select some words or combinations of words that are more indicative of the type of a piece of text. These words or combinations of words are selected from the words and word-groups as they occur in the texts. These more indicative words or combinations of words we call ¿cue-phrases¿. The goal of these methods is to select the most indicative cue-phrases first. The collection of selected words and/or combinations thereof can then be used for training the classification system. To test these selection methods, a number of experiments has been done on a corpus containing cookbook recipes and on a corpus of four-participant meetings. To perform these experiments, a computer program was written. On the recipe corpus we looked at classifying the sentences into different types. Some examples of these types include ¿requirement¿ and ¿instruction¿. On the four-person meeting corpus we tried to learn, using only lexical features, whether a sentence is addressed to an individual or a group. The experiments on the recipe corpus produced good results that showed that, a number of, the used cue-phrase selection methods are suitable for feature selection. The experiments on the four-person meeting corpus where less successful in terms of performance off the classification task. We did see comparable patterns in selection methods, and considering the results of Jovanovic we can conclude that different features are needed for this particular classification task. One of the original goals was to look at ¿addressee¿ in discussions. Are sentences more often addressed to individuals inside discussions compared to outside discussions? However, in order to be able to accomplish this, we must first identify the segments of the text that are discussions. It proved hard to come to a reliable specification of discussions, and our initial definition wasn¿t sufficient.

Abstract

When people request information, they have a variety of means for eliciting the information. In English two of the primary resources for eliciting information include asking questions, making statements about their interlocutor (thereby generating confirmation or revision). But within these types there are a variety of ways that these information elicitors can be designed. The goal of this task is to examine how different languages seek and provide information, the extent to which syntax vs prosodic resources are used (e.g., in questions), and the extent to which the design of information seeking actions and their responses display a structural preference to promote social solidarity.

Abstract

The Papuan languages of the central Solomon Islands are a negatively defined areal grouping: They are those four or possibly five languages in the central Solomon Islands that do not belong to the Austronesian family. Bilua (Vella Lavella), Touo (Rendova), Lavukaleve (Russell Islands), Savosavo (Savo Island) and possibly Kazukuru (New Georgia) have been identified as non-Austronesian since the early 20th century. However, their affiliations both to each other and to other languages still remain a mystery. Heterogeneous and until recently largely undescribed, they present an interesting departure from what is known both of Austronesian languages in the region and of the Papuan languages of the mainland of New Guinea.

Abstract

In this dissertation the perceptual relevance of prevoicing in Dutch was investigated. Prevoicing is the presence of vocal fold vibration during the closure of initial voiced plosives (negative voice onset time). The presence or absence of prevoicing is generally used to describe the difference between voiced and voiceless Dutch plosives. The first experiment described in this dissertation showed that prevoicing is frequently absent in Dutch and that several factors affect the production of prevoicing. A detailed acoustic analysis of the voicing distinction identified several acoustic correlates of voicing. Prevoicing appeared to be by far the best predictor. Perceptual classification data revealed that prevoicing was indeed the strongest cue that listeners use when classifying plosives as voiced or voiceless. In the cases where prevoicing was absent, other acoustic cues influenced classification, such that some of these tokens were still perceived as being voiced. In the second part of this dissertation the influence of prevoicing variation on spoken-word recognition was examined. In several cross-modal priming experiments two types of prevoicing variation were contrasted: a difference between the presence and absence of prevoicing (6 versus 0 periods of prevoicing) and a difference in the amount of prevoicing (12 versus 6 periods). All these experiments indicated that primes with 12 and 6 periods of prevoicing had the same effect on lexical decisions to the visual targets. The primes without prevoicing had a different effect, but only when their voiceless counterparts were real words. Phonetic detail appears to influence lexical access only when it is useful: In Dutch, the presence versus absence of prevoicing is informative, while the amount of prevoicing is not.

Abstract

The aim of this thesis was to gain more insight into spoken-word comprehension and the influence of sentence-contextual information on these processes using ERPs. By manipulating critical words in semantically constraining sententes, in semantic or syntactic sense, and examining the consequences in the electrophysiological signal (e.g., elicitation of ERP components such as the N400, N200, LAN, and P600), three questions were tackled: I At which moment is context information used in the spoken-word recognition process? II What is the temporal relationship between lexical selection and integration of the meaning of a spoken word into a higher-order level representeation of the preceding sentence? III What is the time course of the processing of different sources of linguistic information obtained from the context, such as phonological, semantic and syntactic information, during spoken-word comprehension? From the results of this thesis it can be concluded that sentential context already exerts an influence on spoken-word processing at approximately 200 ms after word onset. In addition, semantic integration is attempted before a spoken word can be selected on the basis of the acoustic signal, i.e. before lexical selection is completed. Finally, knowledge of the syntactic category of a word is not needed before semantic integration can take place. These findings, therefore, were interpreted as providing evidence for an account of cascaded spoken-word processing that proclaims an optimal use of contextual information during spoken-word identification. Optimal use is accomplished by allowing for semantic and syntactic processing to take place in parallel after bottom-up activation of a set of candidates, and lexical integration to proceed with a limited number of candidates that still match the acoustic input

Abstract

This book provides an overview of the grammatical structure of the language Yurakaré, an unclassified and previously undescribed language of central Bolivia. It consists of 8 chapters, each describing different aspects of the language. Chapter 1 is an introduction to the Yurakaré people and their language. Chapter 2 describes the phonology of the language, from the individual sounds to the stress system. In chapter 3 the morphology of Yurakaré is introduced, i.e. the parts of speech, and the different morphological processes. Chapter 4 is a description of the noun phrase and contains information about nouns, adjectives, postpositions and quantifiers. It also discusses the categories associated with the noun phrase in Yurakaré, such as number, possession, collectivity/distributivity, diminutive. In chapter 5, called 'Verbal agreement, voice and valency' there is a description of the argument structure of predicates, how arguments are expressed and how argument structure can be altered by means of voice and valency-changing operations such as applicatives, causative and middle voice. In chapter 6 there is an overview of verbal morphology, apart from the morphology associated with voice, valency and cross-reference discussed in chapter 5. There is also a description of adverbs in the language in this chapter. Chapter 7 discusses formal and functional properties of modal and aspectual enclitics. In chapter 8, finally, the structure of the clause (both simplex and complex) is discussed, including the switch-reference system and word order. The book ends with two text samples.

Abstract

Although sign language-using communities exist in all areas of the world, few sign languages have been documented in detail. Sign languages occur in a variety of sociocultural contexts, ranging from sign languages used in closed village communities to officially recognized national sign languages. They may be grouped into language families on historical grounds or may participate in various language contact situations. Systematic cross-linguistic comparison reveals both significant structural similarities and important typological differences between sign languages. Focusing on information from non-Western countries, this article provides an overview of the sign languages of the world.