Information-seeking tasks with learning or investigative purposes are usually referred to as exploratory search. Exploratory search unfolds as a dynamic process where the user, amidst navigation, trial-and-error and on-the-fly selections, gathers and organizes information (resources). A range of innovative interfaces with increased user control have been developed to support exploratory search process. In this work we present our attempt to increase the power of exploratory search interfaces by using ideas of social search, i.e., leveraging information left by past users of information systems. Social search technologies are highly popular nowadays, especially for improving ranking. However, current approaches to social ranking do not allow users to decide to what extent social information should be taken into account for result ranking. This paper presents an interface that integrates social search functionality into an exploratory search system in a user-controlled way that is consistent with the nature of exploratory search. The interface incorporates control features that allow the user to (i) express information needs by selecting keywords and (ii) to express preferences for incorporating social wisdom based on tag matching and user similarity. The interface promotes search transparency through color-coded stacked bars and rich tooltips. This work presents the full series of evaluations conducted to, first, assess the value of the social models in contexts independent to the user interface, in terms of objective and perceived accuracy. Then, in a study with the full-fledged system, we investigated system accuracy and subjective aspects with a structural model that revealed that, when users actively interacted with all its control features, the hybrid system outperformed a baseline content-based-only tool and users were more satisfied.
Eating activity monitoring through wearable sensors can potentially enable interventions based on eating speed to mitigate the risks of critical healthcare problems such as obesity or diabetes. Eating actions are poly-componential gestures composed of sequential arrangements of three distinct components interspersed with gestures that may be unrelated to eating. This makes it extremely challenging to accurately identify eating actions. The primary reason for the lack of acceptance of state-of-art eating action monitoring techniques include: i) the need to install wearable sensors that are cumbersome to wear or limit mobility of the user, ii) the need for manual input from the user, and iii) poor accuracy if adequate manual input is not available. In this work, we propose a novel methodology, IDEA that performs accurate eating action identification in eating episodes with an average F1-score of 0.92. IDEA uses only a single wrist-worn sensor and provides feedback on eating speed every 2 minutes without obtaining any manual input from the user. %It can also be used to automatically annotate other poly-componential gestures.
Recent trends in computer-mediated communications (CMC) have not only led to expanded instant messaging through the use of images and videos, but have also expanded traditional text messaging with richer content in the form of visual communication markers (VCM) such as emoticons, emojis, and stickers. VCMs could prevent a potential loss of subtle emotional conversation in CMC, which is delivered by nonverbal cues that convey affective and emotional information. However, as the number of VCMs grows in the selection set, the problem of VCM entry needs to be addressed. Furthermore, conventional means of accessing VCMs continue to rely on input entry methods that are not directly and intimately tied to expressive nonverbal cues. In this work, we aim to address this issue, by facilitating the use of an alternative form of VCM entry: hand gestures. To that end, we propose a user-defined hand gesture set that is highly representative of a number of VCMs and a two-stage hand gesture recognition system (trajectory-based, shape-based) that can identify these user-defined hand gestures with an accuracy of 82%. By developing such a system, we aim to allow people using low-bandwidth forms of CMCs to still enjoy their convenient and discreet properties, while also allowing them to experience more of the intimacy and expressiveness of higher-bandwidth online communication.
Towards User-Adaptive Visualizations: Comparing and Combining Eye-Tracking and Interaction Data for the Real-Time Prediction of User Cognitive Abilities
EventAction: A Visual Analytics Approach to Explainable Recommendation for Event Sequences
Special Issue on Highlights of ACM Intelligent User Interface
The explanation interface has been recognized important in recommender systems because it can allow users to better judge the relevance of recommendations to their preference and hence make more informed decisions. In different product domains, the specific purpose of explanation can be different. For high-investment products (e.g., digital cameras, laptops), how to educate the typical type of new buyers about product knowledge and consequently improve their preference certainty and decision quality is essentially crucial. With this objective, we have developed a novel tradeoff-oriented explanation interface that particularly takes into account sentiment features as extracted from product reviews to generate recommendations and explanations in a category structure. In this manuscript, we report two user studies conducted on this interface. The first is an online user study (in both before-after and within-subjects setups) that compared our prototype system with the traditional one that purely considers static specifications for explanation. The experimental results reveal that adding sentiment-based explanations can help increase users' product knowledge, preference certainty, perceived information usefulness, perceived recommendation transparency and quality, and purchase intention. Inspired by those findings, we performed a follow-up eye-tracking lab experiment in order to in-depth investigate how users view information on the interface. This study shows integrating sentiment features with static specifications in the tradeoff-oriented explanations prompted users to not only view more recommendations from various categories, but also stay longer on reading explanations. The results also infer users' inherent information needs for sentiment features during product evaluation and decision making. At the end, we discuss the work's practical implications from three major aspects, i.e., new users, category interface, and explanation purpose.
Activity recognition is a core component of many intelligent and context-aware systems. We present a solution for discreetly and unobtrusively recognizing common work activities above a work surface without using cameras. We demonstrate our approach, which utilizes an RF-radar sensor mounted under the work surface, in three domains; recognizing work activities at a convenience-store counter, recognizing common office deskwork activities, and estimating the position of customers in a showroom environment. Our examples illustrate potential benefits for both post-hoc business analytics and for real-time applications. Our solution was able to classify seven clerk activities with 94.9% accuracy using data collected in a lab environment and able to recognize six common deskwork activities collected in real offices with 95.3% accuracy. Using two sensors simultaneously, we demonstrate coarse position estimation around a large surface with 95.4% accuracy. We show that using multiple projections of RF signal leads to improved recognition accuracy. Finally, we show how smartwatches worn by users can be used to attribute an activity, recognized with the RF sensor, to a particular user in multi-user scenarios. We believe our solution can mitigate some of users privacy concerns associated with cameras and is useful for a wide range of intelligent systems.