This dissertation seeks to understand how new meanings emerge in the context of institutional change. Existing research seeking to understand shifts in meaning has primarily accessed meaning, across numerous contexts, via the three key constructs of discourse, rhetoric, or framing. Within the context of the emergence of the local food movement in Canada, I employ a mixed methods approach using term frequencies, topic modelling and qualitative content analysis, within a computational grounded theory framework for Big Data analysis. My data consists of all articles containing any mention of the term “local food” in popular Canadian press over 37 years from 1978-2014, a database totalling 31,421 articles. My results show that firstly, new meanings pertaining to local food emerged rapidly over the 37-year period. The emergence of a new meaning for local food, associated with the politicization of food production occurred in the second half of my dataset, whereas the first half was marked by connotations of poverty and hunger, associated with the local food bank. Secondly, unexpected actors were found to significantly impact the propulsion of meaning change, by establishing new vocabularies surrounding the term “local food”. Finally, this dissertation shows that the new meanings associated with local food emerged as a result of discursive opportunities, momentarily arising through the confluence of discourse, rhetoric and framing. I propose an emergent process model of meaning change and, further, propose that discursive opportunity structures can be better understood through the metaphor of an emergent property. / Graduate / 2022-08-01

This study investigated the effect of training in equipment use on science teachers’ Pedagogical Content Knowledge (PCK) about the wave concept. The levels of teachers' reported PCK was explored before and after in-service training through interviews and Content Representations (CoRe). Furthermore, the study extended to investigating how the teachers enacted PCK when teaching the wave concept in their classrooms after the training. This qualitative research followed a case study method with three Grade 10 Physical Sciences teachers who were selected purposefully and pragmatically. Their pedagogical reasoning was elicited through a Video Stimulated Recall (VSR) interview and their general views about the training were obtained through a post-training interview. The framework was adapted from the Refined Consensus Model (RCM) and considered PCK at a topic and concept level, with each realm of PCK being underpinned by the Topic-Specific Pedagogical Content Knowledge (TSPCK) components, namely, the learners’ prior knowledge, the curricular saliency, representations, what is difficult and/or easy to teach and understand, and the conceptual teaching strategies. However, all five TSPCK components were considered. The study was centred on three key ideas in the topic of waves, namely: wavelength; frequency; and superposition. The participants' reported PCK improved and the footprint of the training was visible in the enacted PCK of all of the participants. This study suggests that training on the use of equipment improves teachers’ enacted PCK and this may ultimately lead to improved learner performance. / Dissertation (MEd)--University of Pretoria, 2020. / Science, Mathematics and Technology Education / MEd / Unrestricted

The analysis of mainstream newspaper content has long been mined by communication scholars and researchers for insights into public opinion and perceptions. In recent years, scholars have been examining African-American authored periodicals to obtain similar insights. Hearkening back to the 1950s and 1960s civil rights movement in the United States, the highly-publicized killings of African-American men by police officers during the past several years have highlighted longstanding strained police-community relations. As part of its role as both a reflection of, and an advocate for, the African-American community, African-American journalistic texts contain a wealth of data about African-American public opinion about, and perceptions of, police. In years past, media content analysts would manually sift through newspapers to divine interesting police-related themes and variables worthy of study. But, with the exponential growth of digitized texts, communication scholars are experimenting with computerized text analysis tools like topic modeling software to aid them in their content analyses. This thesis considers to what degree topic modeling software can be used at the exploratory stage of designing a content analysis study to aid in uncovering themes and variables worthy of further investigation. Appendix A contains results of the manual exploratory content analysis. The list of topics generated by the topic modeling software may be found in Appendix B. / Media Studies & Production / Accompanied by one .pdf file: NLG Thesis Appendices Final.pdf

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.