Van Bao Nguyen’s research while affiliated with Grenoble Computer Science Laboratory and other places

This work addresses the evaluation of interaction techniques for decision-making tasks performed by non-experts in the context of multi-objective optimization problems. Such tasks require making trade-offs between antagonistic criteria, according to individual subjective preferences. Evaluating such techniques is made difficult by the subjective nature of such tasks, as well as by a lack of rigorous methods for assessment. Our primary contributions to this problem are two-fold: (1) a set of subjective metrics including decision accuracy, choice satisfaction, and incentives to explore; (2) the use of a pragmatic approach to map these subjective metrics onto objective quantitative measures. To illustrate how this subjective-objective mapping can be performed in a pragmatic manner, we have conducted an experiment involving 177 participants to objectively measure and compare two multi-slider interaction techniques for decision-making tasks performed by non-experts in the context of domestic energy management. The results of this evaluation constitute a secondary contribution.

This article reviews surveys, design spaces, and frameworks related to the design of persuasive interactive systems, with a particular focus on energy. We first propose a cartography of these conceptual tools. Most previous work focuses on persuasion principles but is difficult to apply for the software design and engineering of persuasive interactive systems. As a result, we propose UP+, a new framework that synthetizes and revisits existing surveys, design spaces, and frameworks from the software engineering perspective of persuasive interactive systems. Cet article propose un état de l’art d’espaces de conception et d’études pour les systèmes interactifs persuasifs, en particulier dans le domaine de l’énergie. Nous établissons et proposons une cartographie des principes de persuasion et des caractéristiques des systèmes persuasifs captées par ces outils. Nous observons que la plupart de ces outils sont difficiles à exploiter pour l’ingénierie de ces systèmes. Aussi, à partir de cette cartographie, nous proposons le framework UP+ qui synthétise et revisite ces outils d’un point de vue de l’ingénierie des systèmes interactifs persuasifs.

This thesis is about persuasive interactive systems, a subclass of interactive systems aiming at supporting sustainable behaviors. Persuasive technology is a very recent and emerging topic, which relies on persuasion to support human behavior change voluntarily without coercion and deception.In this research, we focus the design of persuasive system for promoting behaviors change with energy as application domain. In the interest of preserving the planet, reducing domestic energy use is necessary for fighting against global warming and climate change issues. The approach to save energy by introducing more efficient appliances only tackles partially the current issues. An urgent need is to motivate sustainable behaviors in energy usage. However, changing people behaviors involves a complex and difficult process.The challenge is to design interactive systems that take into account this process dimension and that keep users involved over time in the process of behavior change. Consequently, based on a review of classifications, design spaces and frameworks targeting the design of persuasive systems, we propose the UP+ framework, our first and conceptual contribution. It considers three dimensions: two related to the process aspect of behavior change, at two levels: micro (cause-effect-causality) and macro (long term)); one related to the psychological aspects of motivation.Based on the UP+ framework, we conduct a state of the art of existing persuasive systems for energy. It reveals that most of these systems covers a few persuasive functions only (e.g., self-surveillance or eco-feedback). In this work, we particularly focus on decision and causality of behavior. A second contribution is the Mondrian User Interface, a proof-of-concept of UI designed to sustain daily use and to keep inhabitants motivated in the long run. We consider thrre goals: to catch user’s attention; to offer multiple levels of user interaction depending on the context of use; to allow the integration of interactional bricks supporting persuasion. Particularly, we propose two bricks, Sliders4DM and Plan4Actions.In order to assist inhabitants in preparing a change (decision), Sliders4DM is a novel widget allowing non-specialists to find an appropriate trade-off between (possibly) conflicting criteria in the home via what-if approach. Sliders4DM is evaluated with two experiments: a qualitative one (16 participants) and a quantitative comparative one (177 participants). Plan4Actions is a novel concept of user interface for planning daily actions. The concept is empowered by the co-decision between inhabitants and the home management system. It provides inhabitants with flexibility in planning their daily actions in order to satisfy their objectives in terms of comfort and sobriety. A twofold evaluation presented a favorable assessment from 13 participants about Plan4actions’ comprehension, its usability and potential utility in the domestic context.We also discuss the limitations related to persuasive interaction covered by current works and the needs for a long-term evaluation to mesure the behavior changes. The thesis opens new perspectives for extending current research of PIS for energy. To conclude, we define our future works, which involves short-term improvements for current prototype and its deployment in real domestic context.

Reducing energy consumption is an individual and collective challenge that requires people to be proactive and fully involved. However, most approaches and solutions to this problem promote automated and autonomous systems that take full control of the decisions. Although these systems relieve users from setting the temperature in offices and homes, the level of thermal comfort chosen by the technology may not meet the individuals’ requirements. Automating control is an obvious solution but it keeps the human out of the loop. In this paper, an alternative approach is promoted based on system–human cooperation that allows people to make the final decision. However, to make sound decisions, users need to understand the system functioning and rationale and they need to be convinced and motivated to change their habits with regard to energy consumption. Our approach is based on an e-coach system, called Involved, which provides users with contextual explanations along with a user interface designed to persuade the user to stay involved. The results of this research are the development of an early prototype that provides end-users with a 24-hour plan of recommended actions along with contextual explanations that justify each action. This plan satisfies the inhabitant’s preferred compromise between the thermal comfort, air quality and financial cost specified by the inhabitant (i.e. the user) using a novel interaction technique, the Trade-Off-Pareto sliders. Users can edit the plan (e.g. suppress an action), skip some actions, perform additional actions, or even change their preferred compromise, and be informed in real time of the consequences on energy consumption and comfort.

Persuasive technology aims at supporting people to change their attitudes and/or behaviors sustainably. Application areas include energy saving, green mobility, medical observance, addiction, etc. Emergency to solve these societal challenges makes the field meet a great success. We propose UP!, a problem space to structure the exploration of the design space, an increment to the SEPIA framework. UP! combines two perspectives, the User and the Phenomenon under study, so that to create the right system that makes the user understand the problematic phenomenon and act appropriately to change sustainably.

In monomodal approaches, eye-tracking for gaze-based interaction suffers from a tight coupling between perception and action: making the distinction between user action and user perception of information is almost impossible. This paper proposes the concept of progressive feedback to release this coupling. First experiments confirm that gaze-based interaction can be credible in some contexts of use. Moreover, progressive feedback appears as possibly valuable.