This master’s thesis investigates methods for improving accessibility in virtual reality (VR), focusing on avatar control for individuals with limited mobility. VR offers an opportunity to help them with specific rehabilitation. Avatars, representing the user, serve as a bridge between the virtual and physical world, helping with the sense of embodiment and the more control, the better is the rehabilitation, for example. The objective is to identify effective avatar control approaches in VR, excluding traditional body movements, and assess their impact based on four criteria: sense of embodiment, user experience, task workload, and performance. To address this, we designed a VR experiment in Unity3D with two tasks: one for interaction (selection and manipulation) and one for navigation. Each task had two independent variables. One common variable was the input modality (head-tracking or eye-tracking). For interaction, the second variable determined whether participants had to grasp an object to trigger the avatar’s reaction or could directly control the avatar. In navigation, the second variable decided whether participants used steering or triggering mechanisms for navigating towards their destination. A user study using an HTC Vive Pro eye including 24 healthy participants, testing all four conditions for both tasks was conducted. Participants received tutorials before each condition. We recorded run times during each condition, with five runs for interaction and four for navigation. After each condition, participants provided feedback: the Virtual Embodiment Questionnaire assessed sense of embodiment, the NASA Task-Load Index evaluated task workload, and the System Usability Scale gauged user experience. A repeated-measure two-way Anova showed that for interaction, eye-tracking improved speed performance but did not significantly affect the other metrics compared to head-tracking. In navigation, head-tracking consistently outperformed eye-tracking in all aspects. No other significant results were found. In conclusion, this thesis lays a foundation for enhancing VR accessibility by providing insights into input modalities and avatar control methods. / Denna masteruppsats undersöker metoder för att förbättra tillgänglighet i virtuell verklighet (VR), med fokus på avatarstyrning för personer med begränsad rörlighet. VR erbjuder en möjlighet att hjälpa dem med specifik rehabilitering. Avatarer, som representerar användaren, fungerar som en bro mellan den virtuella och den fysiska världen och hjälper till med känslan av förkroppsligande och ju mer kontroll, desto bättre är rehabiliteringen, till exempel. Syftet är att identifiera effektiva metoder för avatarkontroll i VR, med undantag för traditionella kroppsrörelser, och bedöma deras inverkan utifrån fyra kriterier: känsla av förkroppsligande, användarupplevelse, arbetsbelastning och prestanda. För att ta itu med detta utformade vi ett VR-experiment i Unity3D med två uppgifter: en för interaktion (urval och manipulation) och en för navigation. Varje uppgift hade två oberoende variabler. En gemensam variabel var input modality (head-tracking eller eye-tracking). För interaktion bestämde den andra variabeln om deltagarna var tvungna att greppa ett objekt för att utlösa avatarens reaktion eller direkt kunde kontrollera avataren. För navigering avgjorde den andra variabeln om deltagarna använde styr- eller utlösningsmekanismer för att navigera mot sin destination. En användarstudie med en HTC Vive Pro eye genomfördes med 24 friska deltagare, som testade alla fyra villkor för båda uppgifterna. Deltagarna fick handledning före varje villkor. Vi registrerade körtider under varje villkor, med fem körningar för interaktion och fyra för navigering. Efter varje tillstånd gav deltagarna feedback: Virtual Embodiment Questionnaire bedömde känslan av förkroppsligande, NASA Task-Load Index utvärderade arbetsbelastningen och System Usability Scale mätte användarupplevelsen. En repeated-measure two-way Anova visade att för interaktion förbättrade eyetracking hastighetsprestandan men påverkade inte de andra mätvärdena signifikant jämfört med head-tracking. Vid navigering överträffade head-tracking konsekvent eye-tracking i alla avseenden. Inga andra signifikanta resultat hittades. Sammanfattningsvis lägger denna avhandling en grund för att förbättra VR-tillgängligheten genom att ge insikter om inmatningsmodaliteter och avatarstyrningsmetoder.

La Thérapie Avatar (TA) est une nouvelle psychothérapie en réalité virtuelle. Celle-ci a été développée pour traiter les hallucinations auditives verbales (HAV) chez les patients atteints de schizophrénie résistante au traitement (SRT). Diverses composantes psychothérapeutiques, telles que les émotions et le sentiment de présence, pourraient contribuer à la réponse clinique dans le cadre de thérapies psychologiques. De plus, dans le contexte des interventions basées en réalité virtuelle, le sentiment de présence pourrait être associé à la réponse émotionnelle. Néanmoins, ces éléments ont été peu explorés dans le contexte de la TA. Ainsi, ce mémoire visait à explorer les liens entre le sentiment de présence, les émotions et la réponse clinique dans la TA. Pour mener cette étude, les données d’essais de TA antérieurs et en cours ont été utilisées. Au total, les données de 123 participants atteints de SRT ou d’un trouble schizoaffectif résistant au traitement ont été utilisées. Cet échantillon comprenait 84 individus de sexe masculin et 39 individus de sexe féminin, dont l’âge moyen était de 41,9 ans. À la fin de chaque séance de TA, le sentiment de présence et les émotions ressenties lors des séances de réalité virtuelle immersive ont été évalués à l’aide de questionnaires standardisés. Une échelle d’évaluation graphique et le questionnaire de présence Igroup Presence Questionnaire (IPQ) ont été utilisés pour évaluer le sentiment de présence. Une échelle d’évaluation graphique a également été utilisée pour évaluer la réponse émotionnelle. La variation au niveau de la sévérité des HAV a été évaluée à l’aide de la sous-échelle des hallucinations auditives du Psychotic Symptom Rating Scales (PSYRATS-AH). Des corrélations de Spearman ont été utilisées pour évaluer les associations entre le sentiment de présence et les émotions. Les corrélations entre le sentiment de présence et la variation de sévérité des HAV après la TA ont également été évaluées. Un test U de Mann-Whitney a été utilisé pour comparer les scores de sentiment de présence (IPQ et échelle d’évaluation graphique) entre les participants ayant une réduction de 20% ou plus du score au PSYRATS-AH (répondeurs) et les participants ayant eu une réduction de moins de 20 % du score au PSYRATS-AH (non-répondeurs). Les résultats obtenus montraient que le sentiment de présence était positivement corrélé avec le sentiment de contrôle (échelle d’évaluation graphique : rs = 0,337, p < 0,01 ; IPQ : rs = 0,225, p < 0,05). Le même résultat a été observé pour le sentiment de sérénité, mais uniquement avec l’échelle d’évaluation graphique (rs = 0,242, p < 0,05). Aucune association significative n’a été observée entre le sentiment de présence et les émotions négatives (anxiété, colère, peur et tristesse). De plus, un sentiment de présence plus élevé, mesuré à l’aide de l’échelle d’évaluation graphique, était associé à une diminution plus importante des HAV (rs = −0,384, p < 0,01), mais aucune association significative n’a été trouvée avec l’IPQ (rs = −0,257, p = 0,15). Enfin, des scores plus élevés de sentiment de présence étaient associés à une réponse clinique optimale (réduction de 20% ou plus du score au PSYRATS-AH), mais uniquement en utilisant l’échelle d’évaluation graphique (d de Cohen = 0,543, p = 0,047). En conclusion, les émotions positives semblent être associées au sentiment de présence dans la TA, alors que les émotions négatives pourraient ne pas l’être. Le sentiment de présence semble également être impliqué dans la réponse thérapeutique, ce qui suggère que celui-ci pourrait être une composante importante de la réponse clinique. Des résultats différents ont été obtenus pour l’échelle d’évaluation graphique et l’IPQ, ce qui semble indiquer que ces questionnaires pourraient mesurer différents aspects du sentiment de présence. D’autres études seront nécessaires pour confirmer ces observations et pour évaluer l’uniformité des méthodes de mesure du sentiment de présence dans le cadre des interventions en réalité virtuelle. / Avatar therapy (AT) is a novel virtual reality-based psychotherapy that has been developed to treat auditory verbal hallucinations (AVH) in treatment-resistant schizophrenia patients. Studies have shown that various psychotherapeutic components, such as emotions and sense of presence, could contribute to clinical outcomes in psychological interventions. Moreover, in the context of virtual reality-based interventions, sense of presence may be associated with emotional response. Nevertheless, these aspects have seldom been investigated in the context of AT. Therefore, this thesis aimed to explore the interplay between sense of presence, emotions, and clinical outcomes in AT. To conduct this investigation, data from previous and ongoing AT trials were used. Data from a total of 123 participants with treatment-resistant schizophrenia or schizoaffective disorder were used. This sample included 84 individuals of the male sex and 39 individuals of the female sex, with a mean age of 41,9 years. After each AT session, the sense of presence and the emotions that were felt during immersive virtual reality sessions were assessed using standardized questionnaires. A graphic rating scale and the Igroup Presence Questionnaire (IPQ) were used to evaluate the sense of presence. A graphic rating scale was also used to evaluate emotional response. Change in the main clinical outcome, AVH, was evaluated using the auditory hallucinations subscale of the Psychotic Symptom Rating Scales (PSYRATS-AH). Spearman correlations were used to assess the associations between sense of presence and emotions. Correlations between sense of presence and change in AVH after AT were also evaluated. A Mann-Whitney U test was used to compare sense of presence scores (IPQ and graphic rating scale) between participants with a reduction of 20% or more in PSYRATS-AH score (responders) and participants who had a reduction of less than 20% in PSYRATS-AH score (non-responders). Sense of presence was found to be positively correlated with feelings of control (graphic rating scale: rs = 0,337, p <0,01; IPQ: rs = 0,225, p < 0,05). The same was observed for serenity, but only with the graphic rating scale (rs = 0,242, p < 0,05). No significant associations were observed between presence and negative emotions (anxiety, anger, fear and sadness), regardless of the scale. Moreover, a higher sense of presence, measured with the graphic rating scale, was associated with a bigger decrease in AVH (rs = −0,384, p < 0,01), but no significant association was found with the IPQ (rs = −0,257, p = 0,15). Finally, higher levels of sense of presence were associated with a positive clinical outcome (reduction of 20% or more in PSYRATS-AH score) but only when using the graphic rating scale (Cohen’s d = 0,543, p = 0,047). In conclusion, positive emotions seem to be associated with sense of presence in AT, whereas negative emotions might not be. Sense of presence also seems to be involved in the therapeutic outcome, thereby suggesting that this could be an important component related to clinical response. Results differed between the graphic rating scale and the IPQ, which seems to indicate that these questionnaires may measure different aspects of presence. More studies will be needed to confirm these trends, which could be generalized to other psychotherapeutic interventions using virtual reality. Moreover, further studies will be needed to assess the consistency of methods used to measure sense of presence in virtual reality interventions.

In the past few years, e-government has been a topic of much interest among those excited about the advent of Web technologies. Due to the growing demand for effective communication to facilitate real-time interaction between users and e-government applications, many governments are considering installing new tools by e-government portals to mitigate the problems associated with user – interface communication. Therefore, this study is to indicate the use of multimodal metaphors such as audio-visual avatars in e-government interfaces; to increase the user performance of communications and to reduce information overload and lack of trust that is common with many e-government interfaces. However, only a minority of empirical studies has been focused on assessing the role of audio-visual metaphors in e-government. Therefore, the subject of this thesis’ investigation was the use of novel combinations of multimodal metaphors in the presentation of messaging content to produce an evaluation of these combinations’ effects on the users’ communication performance as well as the usability of e-government interfaces and perception of trust. The thesis outlines research comprising three experimental phases. An initial experiment was to explore and compare the usability of text in the presentation of the messaging content versus recorded speech and text with graphic metaphors. The second experimental was to investigate two different styles of incorporating initial avatars versus the auditory channel. The third experiment examined a novel approach around the use of speaking avatars with human-like facial expressions, obverse speaking avatars full body gestures during the presentation of the messaging content to compare the usability and communication performance as well as the perception of trust. The achieved results demonstrated the usefulness of the tested metaphors to enhance e-government usability, improve the performance of communication and increase users’ trust. A set of empirically derived ground-breaking guidelines for the design and use of these metaphors to generate more usable e-government interfaces was the overall provision of the results.

No description available.

Embodied Conversational Agents (i.e., avatars; ECAs) are appearing in increasingly many everyday contexts, such as e-commerce, occupational training, and airport security. Also common to a typical person's daily life is persuasion. Whether being persuaded or persuading, the ability to change another person's attitude or behavior is a thoroughly researched topic. However, little is known about ECAs' ability to persuade and whether basic persuasion principles from human-human interactions will hold in human-ECA interactions. This work investigates this question. First, a broad review of persuasion literature, which serves as an inventory of manipulations to test in ECA contexts, is presented. This literature review serves an inventory to guide future Persuasive ECA work. The ECA literature is then reviewed. Two preliminary studies exploring the effects of physical attractiveness, voice quality, argument quality, common ground, authority, and facial similarity are presented. Finally, the culminating study testing the effectiveness of ECAs to elicit self-disclosure in automated interviewing is presented and discussed. The findings of that automated interviewing study suggest that ECAs may replace humans in automated interviewing contexts. The findings also suggest that ECAs that are manipulated to look like their interviewees are able to induce greater likeability, establish more rapport, and elicited more self-referencing language than ECAs that do not look like the interviewees.

Le sentiment de présence, but ultime de la réalité virtuelle, peut être atteint en stimulant ces quatre "piliers" que sont l'immersion, l'interaction, le maintien de la boucle action-perception et les émotions. Notre objectif est de proposer des méthodes visant à améliorer ce sentiment en s'intéressant plus particulièrement à la perception visuelle. Dans cette optique, nous proposons tout d'abord une solution appliquant le rendu stéréoscopique sur carte graphique. Traditionnellement effectué en deux passes, ce rendu se fait maintenant en une passe, grâce aux shaders et au regroupement de certaines phases de calculs. Nous étendons ce processus de rendu aux tout récents écrans auto-stéréoscopiques nécessitant plus de deux vues, améliorant d'autant plus les temps de calcul. Pour assurer l'immersion et l'interaction, voire l'émotion, nous avons aussi cherché à diminuer la fatigue oculaire induite par les images stéréoscopiques, en ajoutant un flou de profondeur de champ. Ce flou, obtenu en temps réel grâce aux shaders, permet également d'inviter l'observateur à focaliser son attention sur des objets précis au lieu de laisser son regard errer. Enfin, un objectif pour obtenir le sentiment de présence est de faire croire à l'utilisateur qu'il existe dans la scène virtuelle. Notre contribution à ce but, est d'intégrer de manière naturelle une représentation virtuelle de l'utilisateur. Pour cela, nous créons par visual hulls un avatar à l'aide de caméras. Finalement, cet avatar est employé pour illustrer la présence de l'utilisateur au travers de surfaces réfléchissantes virtuelles ou de la projection de son ombre

In this thesis I cover the theoretical framework and the practice based implications of bringing the fundamental principles of a cybernetic art educational strategy, the Groundcourse, which was developed and taught during the 1960’s in England by Roy Ascott, into the virtual, three dimensional builder’s world of the metaverse; to be implemented there as a non-institutional, voluntary, self-directed, adult oriented learning system for avatars – one which is expected to be taught by avatar instructors who will formulate the specifics of their curriculum and their methods based upon the cardinal tenets of the Groundcourse, which have been summarized by Roy Ascott as a flexible structure, “within which everything can find its place, and every individual his way,” which would give dimension and substance to the will to create and to change. In order to be able to set the groundwork for the adaptation of the Groundcourse’s principles to my model I have conducted literature reviews in experiential learning theories, with an emphasis on self-directed learning; as well as cybernetic learning. These I have combined with a survey of play theory and virtual world studies, particularly those focusing upon the avatar and metaverse creativity. From all of these I have woven together a foundation which I have combined with a visual documentation which may serve as case studies for my proposal. The new knowledge embodied through this thesis is a learning system for the creative fields that is designed specifically for the residents of online virtual worlds, and yet has its foundations in an earlier, well established and well regarded model.

Le sentiment de présence, but ultime de la réalité virtuelle, peut être atteint en stimulant ces quatre "piliers" que sont l'immersion, l'interaction, le maintien de la boucle action-perception et les émotions. Notre objectif est de proposer des méthodes visant à améliorer ce sentiment en s'intéressant plus particulièrement à la perception visuelle. Dans cette optique, nous proposons tout d'abord une solution appliquant le rendu stéréoscopique sur carte graphique. Traditionnellement effectué en deux passes, ce rendu se fait maintenant en une passe, grâce aux shaders et au regroupement de certaines phases de calculs. Nous étendons ce processus de rendu aux tout récents écrans auto-stéréoscopiques nécessitant plus de deux vues, améliorant d'autant plus les temps de calcul. Pour assurer l'immersion et l'interaction, voire l'émotion, nous avons aussi cherché à diminuer la fatigue oculaire induite par les images stéréoscopiques, en ajoutant un flou de profondeur de champ. Ce flou, obtenu en temps réel grâce aux shaders, permet également d'inviter l'observateur à focaliser son attention sur des objets précis au lieu de laisser son regard errer. Enfin, un objectif pour obtenir le sentiment de présence est de faire croire à l'utilisateur qu'il existe dans la scène virtuelle. Notre contribution à ce but, est d'intégrer de manière naturelle une représentation virtuelle de l'utilisateur. Pour cela, nous créons par visual hulls un avatar à l'aide de caméras. Finalement, cet avatar est employé pour illustrer la présence de l'utilisateur au travers de surfaces réfléchissantes virtuelles ou de la projection de son ombre / The feeling of presence is the ultimate goal of a virtual reality system. It can be achieved by stimulating its four pillars that are immersion, interaction, consistency of the action-perception loop and emotions. Our objective is submit methods which could increase this feeling of presence. We will especially focus on visual perception. First, we present a solution applying the stereoscopic rendering on GPU. Using the latest shaders extensions, we join the traditional two passes to a single that reduce redundant computation. Our method can also be applied on recent autostereoscopic screens which need about ten different view points. The second contribution refers to eyestrain caused when a user watches stereoscopic images during a long time. We propose to use the graphic cards to render, in real time, a blur on problematic areas thus the user will focus on the others. We also use blur to point out some objects of the virtual scene that we considerate as important and avoid to let user's eye wander. Finally, we propose a method to increase the presence of the user into the virtual environment. An avatar, based on images taken from several cameras and visual hull method, is first build. In a second stage, the avatar is integrated into the virtual scene so it seems natural to the user. Thus we use reflective surfaces like mirrors or virtual lights interactions like shadows

This thesis investigated the use of novel combinations of multimodal metaphors in the presentation of learning information to evaluate the effect of these combinations on the usability of e-learning interfaces and on the users' learning performance. The empirical research described in this thesis comprised three experimental phases. In the first phase, an initial experiment was carried out with 30 users to explore and compare the usability and learning performance of facially animated expressive avatars with earcons and speech, and text with graphics metaphors. The second experimental phase involved an experiment conducted with 48 users to investigate their perception of avatar's facial expressions and body gestures when presented in both the absence and presence of interactive e-learning context. In addition, the experiment aimed at evaluating the role that an avatar could play as virtual lecturer in e-learning interfaces by comparing the usability and learning performance of three different modes of interaction: speaking facially expressive virtual lecturer, speaking facially expressive full-body animated virtual lecturer, and two speaking facially expressive virtual lecturers. In the third phase, a total of 24 users experimentally examined a novel approach for the use of earcons and auditory icons in e-learning interfaces to support an animated facially expressive avatar with body gestures during the presentation of the learning material. The obtained results demonstrated the usefulness of the tested metaphors to enhance e-learning usability and to enable users to attain better learning performance. These results provided a set of empirically derived innovative guidelines for the design and use of these metaphors to generate more usable e-learning interfaces. For example, when designing avatars as animated virtual lecturers in e-learning interfaces, specific facial expression and body gestures should be incorporated due to its positive influence in enhancing learners' attitude towards the learning process.

A proposta desta dissertação aborda o consumo de videogame entre os sexos e como essa relação, tipicamente econômica, perpassa padrões de gosto individuais e afeta a formação de uma relação simbólica: a identidade gamer. A grande área que permeia este estudo está no mundo virtual dos games, principalmente ao elaborar a caracterização e a tipologia dos avatares. Esta dissertação surgiu durante a leitura de material da sociologia britânica, no qual o sociólogo Garry Crawford destacou que existe uma diferenciação no consumo dos games entre homens e mulheres, e esta diferenciação ocorre pelo avatar. Destaca-se que este trabalho se compreende como um estudo interdisciplinar com foco sociológico e nele está presente literatura do game designer, filosofia, antropologia, educação, entre outras áreas que debatem e que teorizam o videogame. Utilizou-se de metodologia mista, quantitativa e qualitativa, para realizar a análise dos personagens e das entrevistas dos jogadores; por conseguinte, destaca-se um capítulo somente para a abordagem metodológica. Ressalta-se que, dos resultados encontrados, sobressaíram-se três caracterizações de avatares (uma inesperada), além da respectiva tipologia; bem como, das entrevistas, aponta-se para uma convergência no consumo dos videogames. Pode-se afirmar, categoricamente, que, na cidade de Porto Alegre, não há uma extensa diferenciação no consumo de games. / The proposal of this dissertation addresses the consumption of video game between the sexes, and this typically economic relation permeates individual patterns of taste and affects the formation of a symbolic relationship, the gamer identity. The great area that permeates this study is in the virtual world of games, especially when elaborating the characterization and typology of the avatars. This dissertation arose during the reading of material from British sociology, where the sociologist Garry Crawford, pointed out that there is a differentiation in the consumption of games between men and women; and this differentiation occurs by the avatar. It should be noted that this work is understood in an interdisciplinary study with a sociological focus, but there has literature of the designer game, philosophy, anthropology, education, among other areas that debate and theorize the video game. It was used the mixed methodology, quantitative and qualitative, of the analysis of the characters and interviews of the players; therefore, a chapter is only highlighted for the methodological approach. It should be emphasized that three avatars characterizations emerged from the results, an unexpected, besides the respective typology. As well as, from the interviews, one points to convergence in the consumption of video games. It can be affirmed, categorically, that in the city of Porto Alegre there is not an extensive differentiation in the consumption of games.