User experience, performance, and social acceptability: usable multimodal mobile interaction

This thesis explores the social acceptability of multimodal interaction in public places with respect to acceptance, adoption and appropriation. Previous work in multimodal interaction has mainly focused on recognition and detection issues without thoroughly considering the willingness of users to adopt these kinds of interactions in their everyday lives. This thesis presents a novel approach to user experience that is theoretically motivated by phenomenology, practiced with mixed-methods, and analysed based on dramaturgical metaphors. In order to explore the acceptance of multimodal interfaces, this thesis presents three studies that look at users’ initial reactions to multimodal interaction techniques: a survey study focusing on gestures, an on-the-street user study, and a follow-up survey study looking at gesture and voice-based interaction. The investigation of multimodal interaction adoption is explored through two studies: an in situ user study of a performative interface and a focus group study using experience prototypes. This thesis explores the appropriation of multimodal interaction by demonstrating the complete design process of a multimodal interface using the performative approach to user experience presented in this thesis. Chapter 3 looks at users’ initial reactions to and acceptance of multimodal interactions. The results of the first survey explored location and audience as factors the influence how individuals behave in public places. Participants in the on-the-street study described the desirable visual aspects of the gestures as playful, cool, or embarrassing aspects of interaction and how gestures could be hidden as everyday actions. These results begin to explain why users accepted or rejected the gestures from the first survey. The second survey demonstrated that the presence of familiar spectators made interaction significantly more acceptable. This result indicates that performative interaction could be made more acceptable by interfaces that support collaborative or social interaction. Chapter 4 explores how users place interactions into a usability context for use in real world settings. In the first user study, participants took advantage of the wide variety of possible performances, and created a wide variety of input, from highly performative to hidden actions, based on location. The ability of this interface to support flexible interactions allowed users to demonstrate the the purposed of their actions differently based on the immediately co-located spectators. Participants in the focus group study discussed how they would go about placing multimodal interactions into real world contexts, using three approaches: relationship to the device, personal meaning, and relationship to functionality. These results demonstrate how users view interaction within a usability context and how that might affect social acceptability. Chapter 5 examines appropriation of multimodal interaction through the completion of an entire design process. The results of an initial survey were used as a baseline of comparison from which to design the following focus group study. Participants in the focus groups had similar motives for accepting multimodal interactions, although the ways in which these were expressed resulted in very different preferences. The desire to use technology in a comfortable and satisfying way meant different things in these different settings. During the ‘in the wild’ user study, participants adapted performance in order to make interaction acceptable in different contexts. In some cases, performance was hidden in public places or shared with familiar spectators in order to successfully incorporate interaction into public places

Understanding user experience of mobile video: Framework, measurement, and optimization

Since users have become the focus of product/service design in last decade, the term User eXperience (UX) has been frequently used in the field of Human-Computer-Interaction (HCI). Research on UX facilitates a better understanding of the various aspects of the user’s interaction with the product or service. Mobile video, as a new and promising service and research field, has attracted great attention. Due to the significance of UX in the success of mobile video (Jordan, 2002), many researchers have centered on this area, examining users’ expectations, motivations, requirements, and usage context. As a result, many influencing factors have been explored (Buchinger, Kriglstein, Brandt & Hlavacs, 2011; Buchinger, Kriglstein & Hlavacs, 2009). However, a general framework for specific mobile video service is lacking for structuring such a great number of factors. To measure user experience of multimedia services such as mobile video, quality of experience (QoE) has recently become a prominent concept. In contrast to the traditionally used concept quality of service (QoS), QoE not only involves objectively measuring the delivered service but also takes into account user’s needs and desires when using the service, emphasizing the user’s overall acceptability on the service. Many QoE metrics are able to estimate the user perceived quality or acceptability of mobile video, but may be not enough accurate for the overall UX prediction due to the complexity of UX. Only a few frameworks of QoE have addressed more aspects of UX for mobile multimedia applications but need be transformed into practical measures. The challenge of optimizing UX remains adaptations to the resource constrains (e.g., network conditions, mobile device capabilities, and heterogeneous usage contexts) as well as meeting complicated user requirements (e.g., usage purposes and personal preferences). In this chapter, we investigate the existing important UX frameworks, compare their similarities and discuss some important features that fit in the mobile video service. Based on the previous research, we propose a simple UX framework for mobile video application by mapping a variety of influencing factors of UX upon a typical mobile video delivery system. Each component and its factors are explored with comprehensive literature reviews. The proposed framework may benefit in user-centred design of mobile video through taking a complete consideration of UX influences and in improvement of mobile videoservice quality by adjusting the values of certain factors to produce a positive user experience. It may also facilitate relative research in the way of locating important issues to study, clarifying research scopes, and setting up proper study procedures. We then review a great deal of research on UX measurement, including QoE metrics and QoE frameworks of mobile multimedia. Finally, we discuss how to achieve an optimal quality of user experience by focusing on the issues of various aspects of UX of mobile video. In the conclusion, we suggest some open issues for future study

Understanding Challenges in Designing Interactions for the Age of Ambient Media

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Usability of vision-based interfaces

Vision-based interfaces can employ gestures to interact with an interactive system without touching it. Gestures are frequently modelled in laboratories, and usability testing should be carried out. However, often these interfaces present usability issues, and the great diversity of uses of these interfaces and the applications where they are used, makes it difficult to decide which factors to take into account in a usability test. In this paper, we review the literature to compile and analyze the usability factors and metrics used for vision-based interfaces.Postprint (published version

Evaluation of ECA Gesture strategies for robust Human-Computer Interaction

Embodied Conversational Agents (ECAs) offer us the possibility to design pleasant and efficient human-machine interaction. In this paper we present an evaluation scheme to compare dialogue-based speaker authentication and information retrieval systems with and without ECAs on the interface. We used gestures and other visual cues to improve fluency and robustness of interaction with these systems. Our tests results suggest that when an ECA is present users perceive fewer system errors, their frustration levels are lower, turn-changing goes more smoothly, the interaction experience is more enjoyable, and system capabilities are generally perceived more positively than when no ECA is present. However, the ECA seems to intensify the users' privacy concerns

A Kinect-Based Interactive System for Home-Assisted Active Aging

Virtually every country in the world is facing an unprecedented challenge: society is aging.Assistive technologies are expected to play a key role in promoting healthy lifestyles in the elderly.This paper presents a Kinect-based interactive system for home-assisted healthy aging, which guides,supervises, and corrects older users when they perform scheduled physical exercises. Interactionstake place in gamified environments with augmented reality. Many graphical user interface elementsand workflows have been designed considering the sensory, physical and technological shortcomingsof the elderly, adapting accordingly the interaction methods, graphics, exercises, tolerance margins,physical goals, and scoring criteria. Experiments involved 57 participants aged between 65 and 80who performed the same physical routine six times during 15 days. After each session, participantscompleted a usability survey. Results provided significant evidence that support (1) the effectivenessof the system in assisting older users of different age ranges, (2) the accuracy of the system inmeasuring progress in physical achievement of the elderly, and (3) a progressive acceptance ofthe system as it was used. As a main conclusion, the experiments verified that despite their poortechnological skills, older people can adapt positively to the use of an interactive assistance tool foractive aging if they experience clear benefits

Brotate and Tribike: Designing Smartphone Control for Cycling

The more people commute by bicycle, the higher is the number of cyclists using their smartphones while cycling and compromising traffic safety. We have designed, implemented and evaluated two prototypes for smartphone control devices that do not require the cyclists to remove their hands from the handlebars - the three-button device Tribike and the rotation-controlled Brotate. The devices were the result of a user-centred design process where we identified the key features needed for a on-bike smartphone control device. We evaluated the devices in a biking exercise with 19 participants, where users completed a series of common smartphone tasks. The study showed that Brotate allowed for significantly more lateral control of the bicycle and both devices reduced the cognitive load required to use the smartphone. Our work contributes insights into designing interfaces for cycling.Comment: 22nd International Conference on Human-Computer Interaction with Mobile Devices and Services (MobileHCI '20), October 5--8, 2020, Oldenburg, German