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The research contained in this thesis involves three interdisciplinary dimensions: Distance Language Education (DLE) as the context of the research, videoconferencing as the technology, and the provision of oral and visual interaction in DLE as the core research problem. Though DLE is increasingly gaining importance at the start of 21st century, the inadequate provision of real-time oral-visual interaction still remains a major deficiency. To be more precise, DLE is still producing language learners who cannot speak the target language. I have outlined the urgency in solving this problem (Wang, 2004a), and it is precisely this urgency that grounds this research. This thesis therefore aims to answer the following central research question: in what ways is oral-visual interaction via videoconferencing able to facilitate L2 acquisition at a distance? In the course of answering the central research question, the following subsidiary questions are closely investigated: 1. What are the needs of distance learners in terms of L2 acquisition? 2. What are the benefits and limitations of videoconferencing-supported oral and visual interaction in the process of L2 acquisition? 3. What are the implications and potential of such interaction for L2 acquisition in distance mode? This thesis is set against a background of research on the importance of interaction in second language (L2) acquisition and the capabilities of Computer Mediated Communication (CMC). Interaction has been regarded as an integral part of communicative language learning, which promotes L2 acquisition (see Gass, 2003; Hall, 1995; Kitade, 2000; Lantolf, 1994; Mitchell & Myles, 1998; Ohta, 1995; Swain & Lapkin,1995). However, the preliminary study in this research established that, in the context of DLE, this interactive dimension has been inadequately provided, and that distance language learners do need an improved platform for L2 acquisition, especially in terms of acquiring speaking skills. The distance factor in distance language education calls for the employment of technology as a medium to provide an interactive platform for oral and visual interaction. Thus, the empirical dimension of this research, involving the participation of both on-campus and distance language learners, witnesses a two-stage evaluation of a particular Internet-based desktop videoconferencing tool, NetMeeting. In this evaluation, NetMeeting was used to conduct videoconferencing sessions, in which the teacher and participants could see and hear each other during the completion of meaning-based tasks. A great deal of original data was collected from the qualitative evaluation in regard to the benefits and limitations of videoconferencing-supported oral and visual interaction in the process of L2 acquisition in distance mode. This evaluation is approached from two aspects: the technological capabilities and pedagogical values of videoconferencing. Recommendations on the use of videoconferencing and videoconferencing task designs are proposed on the basis of the research findings. These recommendations are highly significant for practitioners in this field. Following Murray (1999), a combination of data collection methods was employed in an attempt to effectively explore the scope and depth of the participants' learning experience through videoconferencing. These methods include pre- and post-trial written surveys, in-depth post-session and post-trial interviews, videotaped videoconferencing sessions and the researcher's personal observation. Qualitative data analysis methods were adopted. Particularly important is the use of Varonis and Gass's (1985) model for analysing the negotiation routines during meaning-based task completion. The contributions of this research are manifold. Theoretically, the research updates key definitions in DLE and CMC in keeping with recent developments in each respective field. In so doing, this thesis puts forward a theory of an emerging fourth generation DLE with synchronous oral-visual interaction as its defining feature (Wang & Sun, 2001), and also proposes a new taxonomy in CMC (Wang, 2004). Both theories categorize more precisely the different roles played by different technologies and their implications for different learner goals. Empirically, this research first develops criteria for selecting appropriate videoconferencing tools (Wang & Sun, 2001) and criteria for evaluating the appropriateness of videoconferencing tasks. These two sets of criteria were then applied in the two-stage evaluation of NetMeeting, yielding useful data (Wang, 2004a; Wang, 2004b). This research also contributes to our understanding of videoconferencing task design and performance principles. The significant findings from this research confirm that Internet-based desktop videoconferencing is capable of supporting oral-visual interaction in DLE and leads to significant improvements in L2 acquisition. Most importantly, this study informs future research into the nature of oral-visual interaction enabled by videoconferencing by demonstrating how and in what ways such interaction facilitates L2 acquisition. The rapid development of computer technology makes publishing the contributions of this study an ongoing part of this research, in order to maintain the originality of this study. Some of the findings have been published in top-ranking international journals (see Wang and Sun, 2001; Wang, 2004a; Wang, 2004b). This study addresses a real and urgent need in distance language learning - the provision of oral-visual interaction. Findings from this research shed light on many issues untreated in the literature and in the practices of DLE. They also point to possible future trends in the globalisation of education because the effects of the pedagogical distance between the learner and education provider may be neutralized, or at least, minimized, through the use of CMC.

Aims: The aims of this thesis were to describe and gain an understanding of how people who live in the vicinity of wind turbines are affected by wind turbine noise, and how individual, situational and visual factors, as well as sound properties, moderate the response. Methods: A cross-sectional study was carried out in a flat, mainly rural area in Sweden, with the objective to estimate the prevalence of noise annoyance and to examine the dose-response relationship between A-weighted sound pressure levels (SPLs) and perception of and annoyance with wind turbine noise. Subjective responses were obtained through a questionnaire (n = 513; response rate: 68%) and outdoor, A-weighted SPLs were calculated for each respondent. To gain a deeper understanding of the observed noise annoyance, 15 people living in an area were interviewed using open-ended questions. The interviews were analysed using the comparative method of Grounded Theory (GT). An additional cross-sectional study, mainly exploring the influence of individual and situational factors, was carried out in seven areas in Sweden that differed with regard to terrain (flat or complex) and degree of urbanization (n = 765; response rate: 58%). To further explore the impact of visual factors, data from the two cross-sectional studies were tested with structural equation modelling. A proposed model of the influence of visual attitude on noise annoyance, also comprising the influence of noise level and general attitude, was tested among respondents who could see wind turbines versus respondents who could not see wind turbines from their dwelling, and respondents living in flat versus complex terrain. Results: Dose-response relationships were found both for perception of noise and for noise annoyance in relation to A-weighted SPLs. The risk of annoyance was enhanced among respondents who could see at least one turbine from their dwelling and among those living in a rural in comparison with a suburban area. Noise from wind turbines was appraised as an intrusion of privacy among people who expected quiet and peace in their living environment. Negative experiences that led to feelings of inferiority added to the distress. Sound characteristics describing the amplitude modulated aerodynamic sound were appraised as the most annoying (swishing, whistling and pulsating/throbbing). Wind turbines were judged as environmentally friendly, efficient and necessary, but also as ugly and unnatural. Being negative towards the visual impact of the wind turbines on the landscape scenery, rather than towards wind turbines as such, was strongly associated with annoyance. Self-reported health impairment was not correlated to SPL, while decreased well-being was associated with noise annoyance. Indications of possible hindrance to psycho-physiological restoration were observed. Conclusions: Wind turbine noise is easily perceived and is annoying even at low A-weighted SPLs. This could be due to perceived incongruence between the characteristics of wind turbine noise and the background sound. Wind turbines are furthermore prominent objects whose rotational movement attracts the eye. Multimodal sensory effects or negative aesthetic response could enhance the risk of noise annoyance. Adverse reactions could possibly lead to stress-related symptoms due to prolonged physiological arousal and hindrance to psychophysiological restoration. The observed differences in prevalence of noise annoyance between living environments make it necessary to assess separate dose-response relationships for different types of landscapes.

Virtual simulations and serious games (video game-based technologies applied to teaching and learning) have been incorporated in the teaching and training curricula of a large number of professions including medicine/surgery. Despite their benefits, there are open, fundamental issues regarding simulation quality, multi-modal cue interaction, and the resulting effect on visual quality perception and ultimately on knowledge transfer and retention. Here the results of a series of seven studies that examined the effect of background sound (contextually related and non-related with respect to the visual scene) on the perception of visual quality (defined with respect to texture resolution, polygon count) presented in stereoscopic and non-stereoscopic 3D. Results indicate that the perception of visual quality is dependent on ambient (background) sound. The results of these studies have implications for designers and developers of serious games who typically strive for high quality virtual worlds despite the computational burden associated with doing so. The results of these studies also bring us closer to understanding the role of quality, multi-modal interactions, and their effect on visual quality perception. This thesis is part of a larger effort in developing an understanding of virtual environment rendering quality, multi-modal interactions, user-specific factors and their effect on knowledge transfer and retention. / UOIT

Connaître la géographie de son environnement urbain est un enjeu important pour les personnes déficientes visuelles. Des cartes tactiles en relief sont généralement utilisées mais elles présentent des limitations importantes (nombre limité d'informations, recours à une légende braille). Les nouvelles technologies permettent d'envisager des solutions innovantes. Nous avons conçu et développé une carte interactive accessible, en suivant un processus de conception participative. Cette carte est basée sur un dispositif multi-touch, une carte tactile en relief et une sortie sonore. Ce dispositif permet au sujet de recueillir des informations en double-cliquant sur certains objets de la carte. Nous avons démontré expérimentalement que ce prototype était plus efficace et plus satisfaisant pour des utilisateurs déficients visuels qu'une carte tactile simple. Nous avons également exploré et testé différents types d'interactions avancées accessibles pour explorer la carte. Cette thèse démontre l'importance des cartes tactiles interactives pour les déficients visuels et leur cognition spatiale.

Nous nous intéressons dans cette thèse au problème de l’automatisation du processus de choix et de paramétrage des visualisations en fouille visuelle de données. Pour résoudre ce problème, nous avons développé un assistant utilisateur "VizAssist" dont l’objectif principal est de guider les utilisateurs (experts ou novices) durant le processus d’exploration et d’analyse de leur ensemble de données. Nous illustrons, l’approche sur laquelle s’appuie VizAssit pour guider les utilisateurs dans le choix et le paramétrage des visualisations. VizAssist propose un processus en deux étapes. La première étape consiste à recueillir les objectifs annoncés par l’utilisateur ainsi que la description de son jeu de données à visualiser, pour lui proposer un sous ensemble de visualisations candidates pour le représenter. Dans cette phase, VizAssist suggère différents appariements entre la base de données à visualiser et les visualisations qu’il gère. La seconde étape permet d’affiner les différents paramétrages suggérés par le système. Dans cette phase, VizAssist utilise un algorithme génétique interactif qui a pour apport de permettre aux utilisateurs d’évaluer et d’ajuster visuellement ces paramétrages. Nous présentons enfin les résultats de l’évaluation utilisateur que nous avons réalisé ainsi que les apports de notre outil à accomplir quelques tâches de fouille de données. / In this thesis, we deal with the problem of automating the process of choosing an appropriate visualization and its parameters in the context of visual data mining. To solve this problem, we developed a user assistant "VizAssist" which mainly assist users (experts and novices) during the process of exploration and analysis of their dataset. We illustrate the approach used by VizAssit to help users in the visualization selection and parameterization process. VizAssist proposes a process based on two steps. In the first step, VizAssist collects the user’s objectives and the description of his dataset, and then proposes a subset of candidate visualizations to represent them. In this step, VizAssist suggests a different mapping between the database for representation and the set of visualizations it manages. The second step allows user to adjust the different mappings suggested by the system. In this step, VizAssist uses an interactive genetic algorithm to allow users to visually evaluate and adjust such mappings. We present finally the results that we have obtained during the user evaluation that we performed and the contributions of our tool to accomplish some tasks of data mining.

Dans des situations où la perception visuelle est fortement contrainte ou déficiente, il est nécessaire de rendre perceptible l'information dans une modalité non visuelle, tout en prenant en compte des capacités sensorielles et mnésiques humaines. Par exemple, un non-voyant, souhaitant prendre connaissance d'un itinéraire, devra le parcourir de façon non visuelle et le mémoriser. Cependant, outre l'aspect matériel, la mise en œuvre de solutions alternatives (non visuelles) demeure confrontée aux capacités cognitives de l'utilisateur (compréhension, mémorisation, intégration de plusieurs informations, etc.). L'objet de cette thèse est de contribuer à la conception de techniques d'interactions permettant d'optimiser la transmission non visuelle d'informations. A ces fins, j'ai exploré l'apport de la multimodalité comme moyen d'optimisation permettant d'outrepasser les limites de la mémorisation. Je me suis concentré sur l'étude des techniques d'interaction basées sur les modalités auditives et tactiles, en limitant au maximum l'utilisation de la parole, afin de concevoir des techniques pour des environnements différents (flexibilité), d'optimiser l'utilisation de canaux perceptifs (exploitation des propriétés du son dans des messages audio pour transmettre plus d'informations, par exemple), d'éviter de limiter mes techniques par la barrière de la langue ou de sa compréhension et enfin, pour explorer d'autres solutions que la synthèse vocale seule. Les travaux de ma thèse ont mené à la conception, à l'implémentation et à l'évaluation de techniques d'interaction multimodale non visuelle, en réponse à différents contextes, dont, en particulier, ceux de la transmission d'informations de type <valeur>, <position> (couple de coordonnées) et <itinéraire> (séquence de couples direction-distance). Pour parvenir à concevoir mes interactions, j'ai, tout d'abord, effectué une revue de la littérature, afin d'en extraire les principaux facteurs de conception de techniques d'interaction dédiées à la transmission non visuelle d'information. Puis, j'ai organisé ces facteurs sous la forme d'un cadre d'analyse, sur lequel je me suis appuyé pour concevoir chacune de mes techniques. Trois expériences distinctes ont permis d'évaluer l'influence de facteurs de conception sur l'efficacité des interactions et la satisfaction des utilisateurs vis-à-vis des techniques. Je peux, notamment, citer l'implication des utilisateurs (actif ou passif), la présence d'aides explicites", la transmission de plusieurs informations en parallèle et la modalité principale utilisée et, le type de codage dans lequel est encodée l'information. / In situations where the visual perception is strongly constraint or deficient, it is necessary to make perceptible the information with a "not visual form" while taking into account human sensory and mnesic capacities. For example, a blind person wishing to acquaint an itinerary must read it under a non visual form and memorize it. However, besides the material aspect, the implementation of alternatives (non-visual) still faces to the cognitive abilities of the user (comprehension, memorization, integration of various information, etc.). The purpose of this thesis is to contribute to the design of interaction techniques allowing to optimize the transmission not visual of the information. For these purposes, I explored the feature of multimodality as a means of optimization, allowing of exceeding the memorization limits. I focused on the study of interaction techniques based on auditory and tactile modalities and by minimizing the use of the speech, in order to develop techniques for different environments (flexibility), optimize the use of perceptual channels (operating the properties of sound in audio messages to transmit more information, for example), avoid limiting my techniques by the language barrier or understanding and finally, to explore alternatives to the synthesised voice alone. The works of my thesis led to the design, to the implementation and to the evaluation of interaction techniques "non-visual" and "multiform", in answer to different contexts, whom in particular those of the information transmission of type <value>, <position> (pair of coordinates) and <itinerary> (sequence of couples direction-distance). To achieve design my interactions, I have made a review of literature in order to extract the main factors of design of interaction techniques dedicated to the transmission not visual of the information. Then, I have organized these factors in an analytical framework on which I have relied to design each of my techniques. Three separate experiments were led to evaluate the influence of design factors on the effectiveness of interactions and satisfaction towards users of technology. I can give some of them, the involvement of users (active or passive), the presence of explicit help, the transmission of several information in parallel, the main modality used and the type of coding in which is encoded the information.

Ensemble simulation is a commonly used technique in operational forecasting of weather and floods. Multi-member ensemble output is usually large, multivariate, and challenging to interpret interactively. Forecast meteorologists and hydrologists are interested in understanding the uncertainties associated with the simulation; specifically variability between the ensemble members. The visualization of ensemble members is currently accomplished through spaghetti plots or hydrographs. To improve visualization techniques and tools for forecasters, we conducted a userstudy to evaluate the effectiveness of existing uncertainty visualization techniques on 1D and 2D synthetic datasets. We designed an uncertainty evaluation framework to enable easier design of such studies for scientific visualization. The techniques evaluated are errorbars, scaled size of glyphs, color-mapping on glyphs, and color-mapping of uncertainty on the data surface. Although we did not find a consistent order among the four techniques for all tasks, we found that the efficiency of techniques used highly depended on the tasks being performed. Errorbars consistently underperformed throughout the experiment. Scaling the size of glyphs and color-mapping of the surface performed reasonably well. With results from the user-study, we iteratively developed a tool named ‘Noodles’ to interactively explore the ensemble uncertainty in weather simulations. Uncertainty was quantified using standard deviation, inter-quartile range, width of the 95% confidence interval, and by bootstrapping the data. A coordinated view of ribbon and glyph-based uncertainty visualization, spaghetti plots, and data transect plots was provided to two meteorologists for expert evaluation. They found it useful in assessing uncertainty in the data, especially in finding outliers and avoiding the parametrizations leading to these outliers. Additionally, they could identify spatial regions with high uncertainty thereby determining poorly simulated storm environments and deriving physical interpretation of these model issues. We also describe uncertainty visualization capabilities developed for a tool named ‘FloodViz’ for visualization and analysis of flood simulation ensembles. Simple member and trend plots and composited inundation maps with uncertainty are described along with different types of glyph based uncertainty representations. We also provide feedback from a hydrologist using various features of the tool from an operational perspective.

Climate analysts use Coupled Model Intercomparison Project Phase 5 (CMIP5) simulations to make sense of models performance in predicting extreme events such as heavy precipitation. Similarly, weather analysts use numerical weather prediction models (NWP) to simulate weather conditions either by perturbing initial conditions or by changing multiple input parameterization schemes, e.g., cumulus and microphysics schemes. These simulations are used in operational weather forecasting and for studying the role of parameterization schemes in synoptic weather events like storms. This work addresses the need for visualizing the differences in both CMIP5 and NWP model output. This work proposes three glyph designs used for communicating CMIP5 model error. It also describes Ensemble Visual eXplorer tool that provides multiple ways of visualizing NWP model output and the related input parameter space. The proposed interactive dendrogram provides an effective way to relate multiple input parameterization schemes with spatial characteristics of model uncertainty features. The glyphs that were designed to communicate CMIP5 model error are extended to encode both parameterization schemes and graduated uncertainty, to provide related insights at specific locations such as storm center and the areas surrounding it. The work analyzes different ways of using glyphs to represent parametric uncertainty using visual variables such as color and size, in conjunction with Gestalt visual properties. It demonstrates the use of visual analytics in resolving some of the issues such as visual scalability. As part of this dissertation, we evaluated three glyph designs using average precipitation rate predicted by CMIP5 simulations, and Ensemble Visual eXplorer tool using WRF 1999 March 4th, North American storm track dataset.

A global transformation is being fueled by unprecedented growth in the quality, quantity, and number of different parameters in environmental data through the convergence of several technological advances in data collection and modeling. Although these data hold great potential for helping us understand many complex and, in some cases, life-threatening environmental processes, our ability to generate such data is far outpacing our ability to analyze it. In particular, conventional environmental data analysis tools are inadequate for coping with the size and complexity of these data. As a result, users are forced to reduce the problem in order to adapt to the capabilities of the tools. To overcome these limitations, we must complement the power of computational methods with human knowledge, flexible thinking, imagination, and our capacity for insight by developing visual analysis tools that distill information into the actionable criteria needed for enhanced decision support. In light of said challenges, we have integrated automated statistical analysis capabilities with a highly interactive, multivariate visualization interface to produce a promising approach for visual environmental data analysis. By combining advanced interaction techniques such as dynamic axis scaling, conjunctive parallel coordinates, statistical indicators, and aerial perspective shading, we provide an enhanced variant of the classical parallel coordinates plot. Furthermore, the system facilitates statistical processes such as stepwise linear regression and correlation analysis to assist in the identification and quantification of the most significant predictors for a particular dependent variable. These capabilities are combined into a unique geovisual analytics system that is demonstrated via a pedagogical case study and three North Atlantic tropical cyclone climate studies using a systematic workflow. In addition to revealing several significant associations between environmental observations and tropical cyclone activity, this research corroborates the notion that enhanced parallel coordinates coupled with statistical analysis can be used for more effective knowledge discovery and confirmation in complex, real-world data sets.