京都大学 / 0048 / 新制・課程博士 / 博士(情報学) / 甲第17925号 / 情博第507号 / 新制||情||90(附属図書館) / 30745 / 京都大学大学院情報学研究科知能情報学専攻 / (主査)教授 西田 豊明, 教授 河原 達也, 教授 黒橋 禎夫 / 学位規則第4条第1項該当 / Doctor of Informatics / Kyoto University / DGAM

This thesis investigates the impact of the voice modality on user trust in conversational chatbot interfaces. The assumption is that trust can be increased by adding voice output to a chatbot and by a higher quality of a used text-to-speech synthesis. The thesis first introduces chatbots and the concept of conversational interfaces then defines trust in an online context. Based on this, a model for trust and perceiving factors for credibility, ease of use and risk is defined. An online experiment is conducted where participants run through conversational scenarios with a chatbot while varying the voice output. Followed by a survey to collect data about the perception of the trust factors for a scenario with no voice and two scenarios with different speech synthesis qualities. To analyse the ordinal data from the survey the ”Wilcoxon signed- rank test”, a nonparametric statistical test, is conducted to compare trust for the voice output types. Results show that adding the voice output modality to a conversational chatbot interface increases the user trust towards the service. Furthermore, the assumption that synthesis quality has an effect on trust could not hold true because the results are not statistically significant. On this basis, the limitations of the used methods are discussed and suggestions for further research are proposed. / Detta examensarbete undersöker den inverkan som röstmodaliteten har på användarförtroende i konversationsbaserade gränssnitt för chatbottar. Antagandet är att förtroendet kan ökas, dels genom att addera röstutmatning till chatbotten och dels genom att text-till-röst-syntesen ges hög kvalité. Först introduceras chatbottar och konceptet konversationsbaserade gränssnitt. Därefter definieras örtroende i en online-kontext. Baserat på detta definieras en modell för förtroende samt uppfattningsfaktorer för trovärdighet, lättanvändhet och risk. Ett onlineexperiment utfördes, där deltagare går igenom konversationscenarion med en chatbot medan röstutmatningen varieras. Därefter följde en undersökning ämnad att samla in data om uppfattningen om förtroendefaktorerna för ett scenario utan röst och två scenarion med olika talsyntes-kvalitéer. För att analysera den ordnade datan från undersökningen genomfördes Wilcoxon signedrank-testet, ett ickeparametriskt statistiskt test, för att jämföra förtroenden för de olika röstutmatningstyperna. Resultaten visar att addering av röstutmatningsmodalitet till ett konversationsbaserat chatbotsgränsnitt ökar användares förtroende för tjänsten. Vidare, antagandet att synteskvalitén har effekt på förtroendet kunde inte verifieras därför att resultaten inte är statistiskt signifikanta. Begränsningarna hos de använda metoderna diskuteras och förslag för framtida forskning läggs fram.

Ces dernières années, les progrès en sciences de la gestion et de l’information ont transformé la Gestion de Processus d’Affaires (Business Process Management, BPM) en un sujet important, tant du côté de l’industrie que de celui de la recherche. Le BPM utilise des processus métiers pour améliorer la performance opérationnelle des organisations. Les processus métiers établissent un lien entre les personnes, les systèmes, et les différentes organisations, dans le but de créer de la valeur pour les parties prenantes. La cible de notre travail est la famille des systèmes BPM. Un système BPM est un système logiciel générique guidé par des modèles explicites de processus métier avec pour objectif d’exécuter et de gérer des processus opérationnels. Malgré le vaste éventail de sujets traités par ce domaine de recherche, il reste encore quelques questions qui méritent une étude plus approfondie. Un problème particulier concerne la médiation entre les systèmes BPM et les humains. L’interaction homme-machine dans ces systèmes repose sur des interfaces standard basées sur des listes de taches et des formulaires, ce qui est très contraignant pour les utilisateurs.Ceux-ci ont non seulement des difficultés à exécuter leurs processus métier, mais aussi a trouver le processus métier le mieux adapté à leurs besoins. Il serait beaucoup plus efficace d’utiliser des dialogues en langage naturel. Malheureusement les langages de modélisation de processus ne permettent pas de capturer ni de modéliser un domaine de discours. Le travail présent propose une approche originale de gestion du dialogue basée sur des systèmes multi-agents pour l’exécution des processus métier. La motivation globale pour ce travail fut de concevoir un modèle de dialogue extensible à différents domaines. Ce modèle s’appuie sur les ontologies de domaine, nécessitant un minimum d’effort d’adaptation pour améliorer l’interaction. Les résultats montrent tout le potentiel de notre approche multi-agent pour réaliser une médiation automatiquement, sans qu’il soit nécessaire de reconstruire les modèles de processus métier. / Over the last few years, the advances in management science and information technology have transformed the business process management (BPM) discipline into an important topic for both industry and academy. BPM uses business processes as the means for improving the operational performance of organizations, and setting processes are at the heart of BPM allows linking together people, systems, and different organizations to deliver value to stakeholders. The target of our work is the family of BPM systems. A BPM system is a generic software system that is driven by explicit process designs to enact and manage operational business processes. Despite the wide range of topics addressed by the academy on business processes, there are still aspects not addressed by prior research. A particular problem in this regard is the mediation between BPM systems and humans. Human interaction in those systems follows a standard user interface based predominantly on work item lists and forms. Thus, there is little room for creativity for users. They have not only difficulties in enacting their processes but also for searching the most suitable one for their needs. It would be more efficient to let humans interact in natural language. However, process modeling languages are an insufficient means of capturing and representing the domain of discourse. The present thesis develops an original approach to agent dialog management for the problem of business process enactment. The overarching motivation for this work was to design a dialog model scalable to different domains. The model relies on domain and business process ontologies, and necessitates a minimum effort of adaptation on ontologies to improve the interaction. Results indicate the potential of our agent-based approach to generate natural language.

This study evaluates the perceived credibility of a technical chatbot based on its communication style - the way it interacts with its users embodied through text and emojis. A chatbot’s initial communication style was compared to a humble version. The humble communication style was developed from a design workshop held together with six participants and is presented in this paper as a design style guide. The perceived credibility was divided into six dimensions; Competence, Goodwill, Honesty, Predictability, Reputation, and Trustworthiness. The results from the evaluation of the two chatbot versions showed that the credibility was, in general, perceived higher for the chatbot using a humble communication style. Two exceptions were found; (1) the dimension of Trustworthiness stayed at the same level between the versions, and (2) the dimension of Goodwill was perceived higher for the chatbot not using the humble communication style. The satisfaction with the chatbot was measured and resulted in an NPS of 17 for the chatbot using the humble communication style compared to a negative score of -16 for the chatbot not using it. This study found that a more humble communication style would not harm the perceived credibility of a technical professional chatbot. / Den här studien utvärderar den upplevda trovärdigheten hos en teknisk chatbot baserat på dess kommunikationsstil - hur den interagerar med sina användare genom text och emojis. En chatbots initiala kommunikationsstil jämfördes med en ödmjuk version. Den ödmjuka kommunikationsstilen utvecklades från en designworkshop och presenteras i denna studie som en designguide. Den upplevda trovärdigheten delades upp i 6 dimensioner; Kompetens, Välvilja, Ärlighet, Förutsägbarhet, Rykte, och Pålitlighet. Resultatet av utvärderingen av de två chatbot versionerna visade att trovärdigheten upplevdes generellt högre för den ödmjukare chatboten. Två undantag påvisades dock; (1) Pålitlighet blev oförändrad mellan de två kommunikationsstilarna, och (2) Välvilja resulterade i ett högre värde hos den initiala kommunikationsstilen. Användarnas tillfredsställelse med chatboten utvärderades och resulterade i ett NPS värde på 17 för chatboten som använde den ödmjuka kommunikationsstilen igämförelse med ett negativt värde på -16 för chatboten som använde den initiala kommunikationsstilen. Denna studie visade att en mer ödmjuk kommunikationsstil inte skadar den upplevda trovärdigheten hos en teknisk professionell chatbot.

[pt] O presente estudo parte da premissa de que novas formas de se comunicar surgem ao longo dos anos, inclusive na relação entre o humano e a máquina, onde, atualmente, a fala é o veículo comunicacional predominante. E nesse diálogo há uma busca para a adequação da máquina à nossa forma de comunicação e uma constante necessidade de adequação dos seres humanos à forma de comunicação da máquina. Essa investigação visa elucidar se sistemas baseados em interfaces de voz compõe o modelo de interação fundado no que se define como conversa, sendo amparados pelas áreas da ergonomia e usabilidade e por fundamentos provenientes da teoria da conversação. Este trabalho encontra-se estruturado em quatro seções: a primeira equivale a fundamentação teórica; a segunda seção abrange o levantamento de dados através de entrevistas com usuários de interfaces conversacionais; a terceira seção constitui-se na análise de conteúdo das entrevistas; e por fim, a quarta seção envolve as considerações em torno das experiências no uso de interfaces conversacionais atuais. / [en] The present study starts from the premise that new ways of communication are emerging throughout the years, including the relationship between human and machine, which nowadays, speech is the predominant communicational vehicle. And in this dialogue, there is a search for the adaptation of the machine to our form of communication and a constant need to human s adaptation to the machine s form of communication. This investigation attempts to clarify if systems based on voice interfaces are in fact composed by a model of interaction that is defined as conversation, and if they are actually being supported by the areas of ergonomics, usability, and also by the basics fundaments of conversation theory. This work finds itself structured in four sections: the first one corresponds to the theoretical foundations; the second section embraces data collection, which gathered several interviews with the users of conversational interfaces; the third section is established on the content analysis of the previous interviews; lastly, the fourth section concerns the final considerations of the current experience of conversational interfaces.