Writing coherent essays is evidence of a university student's discourse competence and is important in terms of academic success. An analytical taxonomy of coherence breaks {both topic-related and cohesion-related), based on Wikborg (1985; 1990), was used to determine the frequency of coherence breaks in essays written by first-year English Second Language (ESL) students. A subset of these essays was selected for assessment of their holistic coherence (HCR) by raters. The major finding of the statistical tests is that there is a significant relationship between the frequency of coherence breaks, particularly topic-related coherence breaks, and holistic coherence. Furthermore, the relationship between the coherence of essays and marks awarded them was established. Tutor intervention was also found to have had a positive impact when draft and final versions were compared: in general, there was a decrease in the frequency of coherence breaks, and a greater perception of coherence in the final versions. / Linguistics and Modern Languages / M.A. (Linguistics)

Writing coherent essays is evidence of a university student's discourse competence and is important in terms of academic success. An analytical taxonomy of coherence breaks {both topic-related and cohesion-related), based on Wikborg (1985; 1990), was used to determine the frequency of coherence breaks in essays written by first-year English Second Language (ESL) students. A subset of these essays was selected for assessment of their holistic coherence (HCR) by raters. The major finding of the statistical tests is that there is a significant relationship between the frequency of coherence breaks, particularly topic-related coherence breaks, and holistic coherence. Furthermore, the relationship between the coherence of essays and marks awarded them was established. Tutor intervention was also found to have had a positive impact when draft and final versions were compared: in general, there was a decrease in the frequency of coherence breaks, and a greater perception of coherence in the final versions. / Linguistics and Modern Languages / M.A. (Linguistics)

B. Štěpánková K funkci výrazů částicové povahy ve výstavbě textu... ABSTRACT This dissertation is devoted to a specific type of particle unit which we refer to as the actualizer. Actualizers are differentiated from other particles primarily due to a combination of the following properties: the ability to imply a presupposition and the ability to actualize or emphasize a nearby expression. They play an important role in the topic-focus articulation of a sentence by drawing attention to elements with a greater degree of communicative dynamism, not only in focus or contrastive topic, but also in other parts of the sentence. Unlike previous studies which have concentrated mainly on prototypical representatives of these units, this dissertation tries to capture the greatest possible number of actualizers. At the same time, it aims to describe their semantic characteristics, and based on this, it attempts to categorize actualizers into three semantic groups. From this perspective, we can distinguish between restrictive, inclusive, and temporally emphasizing actualizers. These groups can be further divided according to their specific features. The dissertation also analyzes the possible positioning of the actualizers in various places in a sentence and investigates which expressions can occur in the surroundings...

Information extraction from large corpora can be a useful tool for many applications in industry and academia. For instance, political communication science has just recently begun to use the opportunities that come with the availability of massive amounts of information available through the Internet and the computational tools that natural language processing can provide. We give a linguistically motivated interpretation of topic modeling, a state-of-the-art algorithm for extracting latent semantic sets of words from large text corpora, and extend this interpretation to cover issues and issue-cycles as theoretical constructs coming from political communication science. We build on a dynamic topic model, a model whose semantic sets of words are allowed to evolve over time governed by a Brownian motion stochastic process and apply a new form of analysis to its result. Generally this analysis is based on the notion of volatility as in the rate of change of stocks or derivatives known from econometrics. We claim that the rate of change of sets of semantically related words can be interpreted as issue-cycles, the word sets as describing the underlying issue. Generalizing over the existing work, we introduce dynamic topic models that are driven by general (Brownian motion is a special case of our model) Gaussian processes, a family of stochastic processes defined by the function that determines their covariance structure. We use the above assumption and apply a certain class of covariance functions to allow for an appropriate rate of change in word sets while preserving the semantic relatedness among words. Applying our findings to a large newspaper data set, the New York Times Annotated corpus (all articles between 1987 and 2007), we are able to identify sub-topics in time, \\\\textit{time-localized topics} and find patterns in their behavior over time. However, we have to drop the assumption of semantic relatedness over all available time for any one topic. Time-localized topics are consistent in themselves but do not necessarily share semantic meaning between each other. They can, however, be interpreted to capture the notion of issues and their behavior that of issue-cycles.

本論文首先從三個面向討論中文對話中的主題不連續現象。第一、當說話者改變主題的時候，停頓較長、話語的自我修正較多，且很少被打斷。第二、說話者可以直接進入新的主題，或者在談論新主題之前提供一些背景訊息。最常使用來引介新主題的是問句，因為說話者可以藉由提出問題邀請其他人一起討論新話題。第三、說話者在開啟話題時通常會利用各種情境資源，包括周遭的環境、說話者共有的背景知識以及在前文談論過的人、事、時、地、物。目前的語料顯示大多數的新主題都與前文有某種程度的關聯。 研究結果亦指出不同層次的對話主題之差異。當說話者引介最高階的對話主題時，他們傾向使用共有的背景知識，並在主題改變的地方提供背景訊息; 他們的話語有較長的停頓和較多自我修正的情境;。相較之下，在開啟其他階層的對話主題時，說話者較常利用前文出現過的訊息，且不傾向在話題一開始的時候提供背景訊息; 他們的話語也較流暢。然而，不同層次的對話主題也有一些共通點。例如，在各個階層中，說話者普遍使用問句引介新話題，而當他們利用前文的訊息改變話題時，新的主題通常和前一個主題有相同的指示對象。 / The present study aims at investigating topic discontinuity in Chinese daily conversations. This pragmatic phenomenon is discussed from three perspectives. First, since changing topics requires more cognitive effort, the speaker who initiates the change is likely to produce longer pauses and repairing utterances, and is fairly unlikely to be overlapped. Second, the speaker can move to a new topic directly, or orient a new topic in various ways. Questions are the most common backgrounded clauses at the topic-shift boundary because they function to invite other speakers to join the new subject. Third, the speaker most frequently draws on some contextual resource to guide other speakers into conversing about the new topic. The most common way is by recycling the prior text. Speech disfluency, grounding, and contextual resources are also found to distinguish various levels of conversational topics. The highest level of conversational topics are usually grounded in general background knowledge, produced with more disfluency, and tend to begin with background information. The other levels of conversational topics, however, are more likely to arise from prior text, more fluently brought up, and do not use background information more often than foreground information at the topic-initial position. Despite the above-mentioned differences, the various levels of conversational topics are similar in several aspects. For example, backgrounded clauses at the topic-shift boundary are mainly questions; topics grounded in prior text predominantly maintain referential continuity across the topical boundary

Um dos fenômenos mais investigados na literatura sintática recente sobre o português brasileiro (PB), dentro do quadro teórico gerativista e também de outras teorias linguísticas, é aquele que se refere ao que viria a ficar conhecido como tópico-sujeito. Este trabalho se debruçou sobre este fenômeno sintático, mais especificamente, o tópico-sujeito locativo, um tipo de tópico-sujeito em que um constituinte com interpretação locativa figura em posição pré-verbal. Os aspectos investigados mais de perto referem-se à grade argumental e à estrutura eventiva dos verbos envolvidos, bem como ao modo de licenciamento dos dois DPs participantes da estrutura eventiva que expressa a relação locativa. Depois de uma revisão da literatura relevante sobre o tópico-sujeito e as bases do gerativismo, a hipótese derivacional que assumimos neste trabalho considerou uma estrutura semelhante à das sentenças transitivas sem, no entanto, a projeção de Voice agentivo. Postulamos, em seu lugar, um núcleo aplicativo alto, com traços de pessoa, que identifica um evento apto a receber uma locação e introduz um novo participante afetado, com uma relação temática locativa entre ele e o VP. Do ponto de vista diacrônico, supomos que o parâmetro envolvido no aparecimento do tópico locativo na gramática do PB estaria na mesma rede paramétrica relacionada à mudança no parâmetro do sujeito nulo. Foi feita também uma pesquisa com corpora históricos abrangendo o período dos séculos XIX ao XXI, com o objetivo de rastrear um possível desenvolvimento das construções com sintagmas locativos em posição pré-verbal, em variação com os locativos em posição pós-verbal, na expectativa de poder encontrar ocorrências de construções que apresentem as propriedades que identifiquem o tópico-sujeito locativo. Foram utilizados anúncios, cartas pessoais e entrevistas, todos circunscritos ao estado de São Paulo. A metodologia utilizada foi quantitativa e buscou contabilizar variáveis presentes em todas as sentenças com sintagmas de interpretação locativa. / syntactic literature, inside the theoretical frame of the Generative Syntax program and also another linguistic theories, is the one that has come to be known as topic-subject. This work focused on this syntactic phenomenon, more specifically the locative topic, a subtype of topic-subject in which a constituent with locative interpretation appears in a pre-verbal position. The more closely investigated aspects refer to the argument structure and event structure of the verbs involved, as well as to the licensing mode of the two DPs participating in the event structure that expresses the locative relation. After a literature revision about the topic-subject and the foundations of the generative enterprise, the derivational hypothesis that we assume in this work considers a structure similar to that of the transitive sentences without, however, the agentive Voice projection. We consider instead a high applicative head, with person features, whose function is to identify an event capable of receiving a location and to introduce a new affected participant, with a locative thematic relation between it and the VP. From the diachronic point of view, we assume that the parameter involved in the implementation of the locative topic in the BP grammar would be in the same parametric network related to the change in the null subject parameter. Besides, a research was made with historical corpora spanning the period from the nineteenth century to the twenty-first century, aiming to track a probable development of the constructions with locative phrases in pre-verbal position, in variation with locatives in post-verbal position, waiting to find occurrences of constructions showing the topic-subject properties. We used ads, personal letters and interviews, all of which were limited to the state of São Paulo. The methodology used was quantitative and sought to account for variables present in all sentences with phrases associated to locative interpretation.

Background. The randomized controlled clinical trial is currently the most scientific method for evaluating the effect of medical interventions. The sample size of a trial is crucial for reliably estimating the effect. However, many clinical trials may not be sufficiently large in size to detect the effect of interventions assessed. Previous studies of the statistical power, a relative measure of the largeness of a study, were normally small, mainly examined trials with a statistically insignificant result and were flawed because of the biased or purely hypothetical estimate of the effect for the computation of the power. By using meta-analysis, we conducted this study with improved methods for estimating the power and included a larger number of trials. / Findings. A total of 2,923,912 patients from 2,872 clinical trials from 466 systematic reviews were included in the analyses of this thesis. Of the 466 systematic reviews, 24% (113) were identified from the five journals and the remaining 76% (353) were from the Cochrane Library. 1,000 trials and 1,583,204 patients were obtained from 113 systematic reviews identified in the journals, in which 13.7% (95% C.I.: 11.6%, 15.8%) of trials had a sufficient power and the overall power was 34.0% (95% C.I.: 33.7%, 34.3%). 1,872 trials and 1,340,708 patients were obtained from 353 systematic reviews identified in the Cochrane Library, in which 16.7% (95% C.I.: 15.0%, 18.4%) of trials had a sufficient power and the overall power was 37.8% (95% C.I.: 37.6%, 38.0%). (Abstract shortened by UMI.) / Methods. We identified trials from systematic reviews of clinical trials with binary outcomes published in five medical journals and the Cochrane Database of Systematic Reviews. We analyzed the power of trials with a significant result as well as those with an insignificant result. In estimating the power, we used the combined odds ratio of the meta-analysis as the estimate of the effect for trials from systematic reviews with a statistically significant result and a relative risk reduction of 25% for trials from systematic reviews with a statistically insignificant result. In addition to use of the conventional method to estimate the power, we also developed a new "counting method" that does not need any assumption about the effect. Furthermore, the power is also expressed as a relative and absolute difference between the number of subjects required for a power of 80% and that actually recruited by the trials. / Tsoi Kam Fai. / "July 2005." / Adviser: Jin Ling Tang. / Source: Dissertation Abstracts International, Volume: 67-01, Section: B, page: 0161. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (p. 107-113). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese. / School code: 1307.

Zhan Siyan. / "November 2004." / Thesis (Ph.D.)--Chinese University of Hong Kong, 2004. / Includes bibliographical references (p. 133-152) / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web. / Abstracts in English and Chinese.

Les travaux de cette thèse présentent le développement d'algorithmes de classification de documents d'une part, ou d'analyse de réseaux complexes d'autre part, en s'appuyant sur la prétopologie, une théorie qui modélise le concept de proximité. Le premier travail développe un cadre pour la classification de documents en combinant une approche de topicmodeling et la prétopologie. Notre contribution propose d'utiliser des distributions de sujets extraites à partir d'un traitement topic-modeling comme entrées pour des méthodes de classification. Dans cette approche, nous avons étudié deux aspects : déterminer une distance adaptée entre documents en étudiant la pertinence des mesures probabilistes et des mesures vectorielles, et effet réaliser des regroupements selon plusieurs critères en utilisant une pseudo-distance définie à partir de la prétopologie. Le deuxième travail introduit un cadre général de modélisation des Réseaux Complexes en développant une reformulation de la prétopologie stochastique, il propose également un modèle prétopologique de cascade d'informations comme modèle général de diffusion. De plus, nous avons proposé un modèle agent, Textual-ABM, pour analyser des réseaux complexes dynamiques associés à des informations textuelles en utilisant un modèle auteur-sujet et nous avons introduit le Textual-Homo-IC, un modèle de cascade indépendant de la ressemblance, dans lequel l'homophilie est fondée sur du contenu textuel obtenu par un topic-model. / The work of this thesis presents the development of algorithms for document classification on the one hand, or complex network analysis on the other hand, based on pretopology, a theory that models the concept of proximity. The first work develops a framework for document clustering by combining Topic Modeling and Pretopology. Our contribution proposes using topic distributions extracted from topic modeling treatment as input for classification methods. In this approach, we investigated two aspects: determine an appropriate distance between documents by studying the relevance of Probabilistic-Based and Vector-Based Measurements and effect groupings according to several criteria using a pseudo-distance defined from pretopology. The second work introduces a general framework for modeling Complex Networks by developing a reformulation of stochastic pretopology and proposes Pretopology Cascade Model as a general model for information diffusion. In addition, we proposed an agent-based model, Textual-ABM, to analyze complex dynamic networks associated with textual information using author-topic model and introduced Textual-Homo-IC, an independent cascade model of the resemblance, in which homophily is measured based on textual content obtained by utilizing Topic Modeling.

Thesis (M.S.P.H.)--University of South Florida, 2008. / Title from PDF of title page. Document formatted into pages; contains 26 pages. Includes bibliographical references.