Designing mobile, persuasive, and motivational interactions for sustainable behaviour change remains a challenge. Setting daily step goals on a mobile application can initially stimulate participation, but both the number of steps walked each day and the use of mobile applications decrease over time, even when individuals report high levels of motivation. To address this issue, we propose the integration of tailored gamification as a motivational mechanism, grounded in psychological theories. Self-Determination Theory is used to promote competence, while Regulatory Focus Theory is used to support individual differences and for tailoring motivational interactions. Gamification aims at reinforcing motivation and action-taking. In this article, we explain how we designed a motivational mobile application that incorporates these gamification mechanisms, and we describe how we evaluated its use during 28 days with 37 users. Results suggest a decrease in amotivation levels, and that promotion-focused individuals find gamified elements more motivational than prevention-focused ones.

The mobile health market is rapidly developing, but few apps follow evidence-based guidelines. Literature recommends personalized systems grounded in behavioral science, involving healthcare professionals in design to maximize effectiveness. To address this, we propose a metamodel to guide designers. This article discusses its application to low back pain self-management, focusing on four patient profiles: Unmotivated, Cautious, Depressed, and Confident. We evaluated the app over one month with 60 users. Of these, 32 users received a version of the application tailored to their profile, and 28 users received a version of the application without tailoring (no recommendations or motivational messages). We assessed user experience, engagement and psychological characteristics involved in the behavior change process. Results showed satisfactory user experience, impact of tailoring on user behavior and features to reduce fears and false beliefs and increase self-efficacy. Further efforts are needed to increase user engagement and observe an impact on long-term behavior.

This paper presents a study that assesses the effectiveness of Motivational Interviewing (MI) interventions on the engagement of adults over 50 years to do more physical activity. While MI's four step process may easily be adapted to online devices, modeling the MI approach based on empathy may be more challenging (as opposed to directive interviews in which the user is encouraged to adopt a favorable attitude from the outset). Three devices are compared: a non-directive MI-based website, a non-directive MI-based virtual agent and a directed MI-based one. Our results show that the non-directive virtual agent tends to be perceived as more empathetic and trustworthy than the directed one, and that it significantly raises the participants' self-efficacy to overcome barriers, and positively impacts intrinsic motivation. We discuss mentions several implications for the adaptation of MI to the context of ECA.

Low back pain is a major public health problem that is the leading cause of disability in most countries. The recommendations are to propose personalized physical activity programs according to the individual characteristics (motivation, preferences, attitude towards physical activity) of each patient. However, the current management of low back pain includes rehabilitation programs that are costly and/or not always personalized. The objective of this research is to better understand the characteristics of people with chronic low back pain to identify typical profiles to inform the design of a tailored coaching mobile application. We selected eight concepts and associated scales to characterize the population: general health status (MYMOP), treatment burden (TBQ), quality of life (EQ-5D-5L), level (IPAQ), fears and beliefs (FABQ-AP) and motivation (EMAPS) for physical activity, emotional state (PHQ-9) and feeling of self-efficacy (FC-CPSES). These questionnaires were administered online via an e-cohort of low back pain patients. 193 patients with chronic low back pain were included. A clustering analysis allowed us to distinguish 4 profiles: (1) “Unmotivated,” characterized by the lowest motivation and the highest amotivation toward physical activity (i.e., they do not understand why it is useful), (2) “Cautious” with low motivation and having the highest fears and beliefs toward physical activity, (3) “Depressed” with good intrinsic motivation but also a significant level of depressive symptoms, and (4) “Confident” also showing good intrinsic motivation and having the highest self-efficacy. These four profiles of patients will be used to design a coaching mobile application tailored along the priorities (e.g., physical activity, pain management) and types of motivational messages displayed on the tailored mobile application.

Embodied Conversational Agents (ECAs) are suffering from a lack of adoption from users. This paper emphasizes virtual intimacy as a lever to support social dimension of human-agent interaction and enhance user experience. Here, we present an autonomous virtual counselor, expert in tourism, which provides multimodal intimacy-related behaviors. Real tourists interacting in the wild with our intimate agent only perceived its honesty and genuineness, which was insufficient to enhance social presence and user experience. However, our results suggest that the perception of virtual intimacy could be a strong predictor of social presence and user experience. When perceived, virtual intimacy may be, then, an important mean to foster user experience and ECAs adoption.

Building a long-term relationship between human and virtual agent remains a challenge. This paper explores the influence of intimate behavioral cues and the impact of different interaction modalities (voice, text, gesture) on our perception of intimacy. We built a virtual Tourism Information (TI) counselor capable of intimate behaviors based on grounded theories of intimacy developed in psychology. We studied how external observers perceive the social behaviors of the agent during its interactions with a human tourist. Our originality is to evaluate the perception of social skills across the interaction. Our results show that nonverbal behaviors of the virtual agent reinforces the impact of verbal cues on human perception on virtual intimacy. Findings also suggest that textual medium of communication has a negative impact on the perception of virtual intimacy, whatever the level of animation and intimacy exhibited by the TI counselor.

This paper presents a preliminary study which aims to investigate the tangible navigation in 3D Virtual Environments with new tablets (ex. Google Tango) that provide a self-contained 3D full tracking (ex. Google Tango, Intel RealSense). The tangible navigation was compared with tactile navigation techniques used in standard 3D applications (ex. video games, CAD, data visualization). Four conditions were compared: classic multi-touch interaction, tactile interaction with sticks, tangible interaction with a 1:2.5 scale factor and tangible interaction with a 1:5 scale factor. The study focuses on the subjective evaluation users make of the different interaction techniques in terms of usability and acceptability, and the fidelity of representation of the explored scene. Participants were asked to explore a virtual appartment using one of the four interaction techniques. Then, they were requested to draw a 2D sketch map of the explored appartment and to complete a questionnaire of usability and acceptabilty. In order to go further into the investigation, the participant's activity has also been recorded. First results show that exploring a virtual environment using only the device's movements is more usable and acceptable compared to tactile interaction technique, but the difference seems to become smaller as the used scale factor increases.

Artificial agents are becoming artificial companions, interacting with the user on a long-term basis. This evolution brought new challenges to the affective computing domain, such as designing artificial agents with personalities to the benefits of the user. Endowing artificial agents with personality could help to increase the agent's believability, hence easing the interaction. This paper touches on two questions pertaining to computational personality modeling: 1/ how to produce artificial personalities which can inform personality researchers, whether from computer sciences or psychology and 2/ will behaviors produced by artificial agents be perceived by users as putting the programmed personality across as such. We propose to use a data-driven approach to endow artificial agents with personality, using the regulatory focus theory as a framework. We used machine-learned game strategies, in the form of alternative decision trees computed from human data, to convey the personality of artificial agents. We then tested whether these personalities can be perceived by users after playing a game against these agents. We used two artificial agents as controls: one randomly playing and one with an “average / depersonalized” strategy. On the one hand, our results show that agents' regulatory focus, when programmed, can be accurately perceived by users. On the other hand, our results also point out that personality will be perceived by users even if the agent's design does not intend to transmit one.

In a Multi-stereoscopic immersive system, several users sharing the same restricted workspace, e.g. a CAVE, may need to perform independent navigation to achieve loosely coupled collaboration tasks for a complex scenario. In this context, a proper navigation paradigm should provide users both an efficient control of virtual navigation and a guarantee of users' safety in the real workspace relative to the display system and between users. In this aim, we propose several alterations of the human joystick metaphor by introducing implicit adaptive control to allow safe individual navigation for multiple users. We conducted a user study with an object-finding task in a double-stereoscopic CAVE-like system to evaluate both users' navigation performance in the virtual world and their behavior in the real workspace under different conditions. The results highlight that the improved paradigm allows two users to navigate independently despite physical system limitations.

In this article the role of different categories of postures in the detection, recognition, and interpretation of emotion in contextually rich scenarios, including ironic items, is investigated. Animated scenarios are designed with 3D virtual agents in order to test 3 conditions: In the “still” condition, the narrative content was accompanied by emotional facial expressions without any body movements; in the “idle” condition, emotionally neutral body movements were introduced; and in the “congruent” condition, emotional body postures congruent with the character's facial expressions were displayed. Those conditions were examined by 27 subjects, and their impact on the viewers’ attentional and emotional processes was assessed. The results highlight the importance of the contextual information to emotion recognition and irony interpretation. It is also shown that both idle and emotional postures improve the detection of emotional expressions. Moreover, emotional postures increase the perceived intensity of emotions and the realism of the animations.

Consistency and coherence in behaviors are key concepts for creating believable virtual agents. Personality is described by psychology as a set of stable and individualized behaviors. Thus, endowing agents with a personality can help agents to exhibit consistent behaviors. In this paper, we suggest using a socio-cognitive perspective to build a model of personality for virtual agents and to highlight some of the personality structures and processes. Because many researchers in personality psychology emphasize the role of the self in personality, we propose PERSEED, a conceptual model of personality that is based on self-regulation theories.

Analysis of non-verbal behaviors in HCI allows understanding how individuals apprehend and adapt to different situations of interaction. This seems particularly relevant when considering tasks such as speaking in a foreign language, which is known to elicit anxiety. This is even truer for young users for whom negative pedagogical feedbacks might have a strong negative impact on their motivation to learn.

Location-aware ambient environments are relevant in designing interactive virtual characters. However, they raise several questions about spatial behaviors to be displayed by virtual characters, and about the perception of virtual characters by users. We designed a location-aware virtual agent that adapts its spatial behavior to users' and objects' locations during a search task in a smart room. We conducted an experimental evaluation comparing this adaptive agent with an agent that does not perceive nor use the location of users and objects. The location-aware adaptive agent elicited higher levels of perceived presence and perceived adaptivity. Furthermore, performance was less influenced by task difficulty when users interacted with the adaptive agent. Such results can be useful for the design of future location-aware virtual agents.