A Comparative Study of News Exposure and Consumption On and Off FacebookSocial media giants like Meta, Google, and X leverage powerful algorithms to personalize user feeds, a practice now under intense public scrutiny. These algorithms can inadvertently skew the information users consume, potentially influencing political opinions and voting decisions. This raises critical questions: Do social media platforms foster misinformation and contribute to echo chambers? To address this ongoing debate, our study directly compares news exposure on Facebook (where algorithmic influence is strong) with news consumption off-platform (where user behavior plays a larger role). Specifically, we investigate: (1) Are users exposed to more/less misinformation on Facebook compared with their off-platform misinformation consumption? (2) Is news exposure on Facebook more/less diverse than off-platform news consumption? (3) To what extent do socio-demographic and psychological factors influence misinformation exposure and consumption both on and off Facebook? (4) Is there a relationship between socio-demographic and psychological factors and news diversity on and off Facebook? and (5) Is users’ exposure to misinformation on Facebook correlated to off-platform news consumption? The longstanding biggest barrier to answering these questions has been the lack of access to data on what information users see and consume while browsing the Internet. In this paper, we use a measurement approach that asks a panel of users to donate data about the content they see online. For this, we designed a tool to collect traces of all news articles that individuals encounter on their desktop Facebook timeline and while they browse the Internet (off Facebook), along with signals about how users interact with them (e.g., clicks, time spent reading). Our tool observes content and interactions on and off Facebook on 4,149 news media domains sourced from Media Bias Fact Check and NewsGuard. Alongside the news post and article collection, we conduct surveys to gather socio-demographic and psychological data from our participants. Our study of 123,995 news-related posts on Facebook and 70,587 news articles visits off Facebook, collected from 642 users during 12 weeks, reveals the following central findings: (1) Only a small fraction (4%) of users’ news consumption off Facebook is driven by news exposure on Facebook, and only 5.7% of misinformation consumption off Facebook is driven by news exposure on Facebook. (2) There is a higher prevalence of misinformation in user-received content on Facebook compared to deliberately consumed content off-platform. On Facebook, 5.9% of our users’ news exposure comes from sources known for spreading misinformation, while off-platform, only 2.6% of our users’ news consumption is from misinformation sources. Conversely, Facebook presents more diverse content – only 22% of users received content from only one political leaning on Facebook, compared to 36% of users who consumed content from only one political leaning off-platform. (3) Several socio-demographic and psychological factors showed a statistically significant correlation with misinformation exposure on Facebook but not misinformation consumption off Facebook. Finally, (4) the proportion of misinformation consumed off Facebook emerged as a statistically significant predictor of users’ exposure to misinformation on Facebook.2025NANardjes Amieur et al.Misinformation, News, and Fact-CheckingCSCW
Efficient Finger Model and Accurate Tracking for Hover-and-Touch, Mid-air and Microgesture InteractionBare-handed gestural interaction with computer systems is widespread, whether with touchscreens or Augmented Reality headsets. Various forms of gestural interaction exist including hover-and-touch, mid-air and microgesture interaction. Studying the full benefits of these gestural interactions, and their combinations, is currently not possible due to the inadequate performances of the existing tracking solutions. To address this problem, we propose a marker-based visual tracking algorithm with a novel finger model, and its open source implementation (https://iihm.imag.fr/zoppis/maft). A key contribution is the simplicity of the finger and fingertip model (i.e. cylinders and a sphere respectively). This simple model leads to low computational cost (~600 microseconds), high precision (0.02 mm) and accurate (one millimeter) fingertip tracking, without impeding finger movement. We illustrate the benefits of the proposed tracking approach with a demonstration application combining hover-and-touch, mid-air and microgesture interactions for editing a 3D point cloud.2025QZQuentin Zoppis et al.Mid-Air Haptics (Ultrasonic)Hand Gesture RecognitionUIST
An Evaluation of Spatial Anchoring to position AR Guidance in Arthroscopic SurgeryThis work examines spatial anchoring strategies to position augmented reality guidance during surgery. We consider three strategies: anchoring to the Patient, the surgical Tool, and the Surgeon's head. These strategies were evaluated in a first experiment involving 24 non-professional participants, using two guidance techniques: 3D Trajectory and 2D Crosshair. For 3D Trajectory, Patient and Tool anchoring were more precise than Surgeon anchoring, and Patient anchoring was the most preferred. For 2D Crosshair, no significant effect of anchoring strategies on precision was observed. However, participants preferred Patient and Surgeon anchoring. A second experiment with 6 surgeons confirmed the first experiment's results. For 3D trajectory, Tool anchoring proved more precise than Patient anchoring, despite surgeons' preference for Patient anchoring. These findings contribute to empirical evidence for the design of surgical AR guidance, with potential applications for similar, less critical tasks.2025CAChaymae Acherki et al.AREAS; Univ. Grenoble Alpes, LIGAR Navigation & Context AwarenessSurgical Assistance & Medical TrainingCHI
Studying the Simultaneous Visual Representation of MicrogesturesHand microgestures are promising for mobile interaction with wearable devices. However, they will not be adopted if practitioners cannot communicate to users the microgestures associated with the commands of their applications. This requires unambiguous representations that simultaneously shows the multiple microgestures available to control an application. Using a systematic approach, we evaluate how these representations should be designed and contrast 4 conditions depending on the microgestures (tap-swipe and tap-hold) and fingers considered (index and index-middle). Based on the results, we design a simultaneous representation of microgestures for a given set of 14 application commands. We then evaluate the usability of the representation for novice users and the suitability of the representation for small screens compared with a baseline. Finally, we formulate 8 recommendations based on the results of all the experiments. In particular, redundant graphical and textual representations of microgestures should only be displayed for novice users.2024VLVincent LAMBERT et al.Hand Gesture RecognitionMobileHCI
Design and Perception of a Soft Shape Change Beneath a SmartwatchIn this paper, we explore the design of a watch that can deliver notifications through shape changes, specifically focusing on changes in curvature at the back of the watch face. We explain our design choices and challenges while creating such a watch. We conducted an experimental study to determine this novel form of feedback's absolute detection threshold (ADT). We compared the ADT of two watches with a back face that can change curvature and contact the wearer's wrist to notify them. These two watches exhibit different shapes when inflated with high air pressure. We conducted a standard two-down, one-up adaptive staircase procedure to determine the ADT. Our findings show that an ADT of 3.86 psi is required to inflate the back surface for detection by participants. Overall, our qualitative findings indicate that participants enjoyed this novel type of feedback and could feel different sensations with each watch.2024ZFZHUZHI FAN et al.Haptic WearablesShape-Changing Interfaces & Soft Robotic MaterialsMobileHCI
Impact of Fingernails Length on Mobile Tactile InteractionMobile users have fingernails of different lengths. This paper measures the impact of fingernail length on the use of tactile mobile phones. We first conducted interviews with participants wearing long fingernails. They reported difficulties and non-satisfactory coping strategies to hold their phone securely and acquire targets accurately. We then conducted three experiments comparing different lengths of fingernails (0 mm, 5 mm, and 10 mm). Our results quantify the drop in comfort and efficiency. We measured the range of incidental pitch angle on the surface, the comfortable and useful area of the thumb, and the target acquisition efficiency. 10 mm fingernails consistently decrease by 57 % the range of the finger pitch angle, by 36 % the comfortable area of the thumb, and by 24 % the throughput when acquiring targets. This paper contributes guidelines for future inclusive devices and techniques to also support users with long fingernails.2024CCCéline Coutrix et al.CNRS, Université de GrenobleMotor Impairment Assistive Input TechnologiesUniversal & Inclusive DesignCHI
Exploring the Online Micro-targeting Practices of Small, Medium, and Large BusinessesFacebook and other advertising platforms exploit users’ data for marketing purposes by allowing advertisers to select specific users and target them with well-crafted messages (the practice is being called micro-targeting). However, advertisers such as Cambridge Analytica have maliciously used these targeting features to manipulate users in the context of elections. The European Commission plans to restrict or even ban some targeting functionalities in the new European Democracy Action Plan act to protect users from such harms. The difficulty in finding appropriate restrictions is that we do not know the economic impact of these restrictions on regular advertisers. In this paper, to inform the debate, we take a first step by understanding who is advertising on Facebook and how they use the targeting functionalities of ad platforms. For this, we asked 890 U.S. users to install a monitoring tool on their browsers to collect the ads they receive on Facebook and information about how these ads were targeted. By matching advertisers on Facebook with their LinkedIn profiles, we could see that 71% of advertisers are small and medium-sized businesses with 200 employees or less, and they are responsible for 61% of ads and 57% of ad impressions. Regarding micro-targeting, we found that only 32% of small and medium-sized businesses and 30% of large-sized businesses in our datasetet micro-target at least one of their ads. These results should not be interpreted as micro-targeting not being useful as a marketing strategy, but rather that advertisers prefer to outsource the micro-targeting task to ad platforms. Indeed, to deliver ads, Facebook is employing optimization algorithms that exploit user data to decide which users should see what ads; which basically means ad platforms are performing an algorithmic-driven micro-targeting. Hence, when setting restrictions on micro-targeting, legislators should take into account both the traditional advertiser-driven micro-targeting as well as algorithmic-driven micro-targeting performed by ad platforms.2022SCSalim CHOUAKI et al.Business Processes & Worker Advocacy; Business Processes & Worker AdvocacyCSCW
Interaction Pace and User PreferencesThe overall pace of interaction combines the user's pace and the system's pace, and a pace mismatch could impair user preferences (e.g., animations or timeouts that are too fast or slow for the user). Motivated by studies of speech rate convergence, we conducted an experiment to examine whether user preferences for system pace are correlated with user pace. Subjects first completed a series of trials to determine their user pace. They then completed a series of hierarchical drag-and-drop trials in which folders automatically expanded when the cursor hovered for longer than a controlled timeout. Results showed that preferences for timeout values correlated with user pace -- slow-paced users preferred long timeouts, and fast-paced users preferred short timeouts. Results indicate potential benefits in moving away from fixed or customisable settings for system pace. Instead, systems could improve preferences by automatically adapting their pace to converge towards that of the user.2021AGAlix Goguey et al.Université Grenoble AlpesVisualization Perception & CognitionCHI
GyroSuite: General-Purpose Interactions for Handheld Perspective Corrected DisplaysHandheld Perspective-Corrected Displays (HPCDs) are physical objects that have a notable volume and that display a virtual 3D scene on their entire surface. Being handheld, they create the illusion of holding the scene in a physical container (the display). This has strong benefits for the intuitiveness of 3D interaction: manipulating objects of the virtual scene amounts to physical manipulations of the display. HPCDs have been limited so far to technical demonstrators and experimental tools to assess their merits. However, they show great potential as interactive systems for actual 3D applications. This requires that novel interactions be created to go beyond object manipulation and to offer general-purpose services such as menu command selection and continuous parameter control. Working with a two-handed spherical HPCD, we report on the design and informal evaluations of various interaction techniques for distant object selection, scene scaling, menu interaction and continuous parameter control. In particular, our design leverages the efficient two-handed control of the rotations of the display. We demonstrate how some of these techniques can be assemble in a self-contained anatomy learning application. Novice participants used the application in a qualitative user experiment. Most participants used the application effortlessly without any training or explanations.2020TLThibault Louis et al.Full-Body Interaction & Embodied InputMixed Reality WorkspacesImmersion & Presence ResearchUIST
PickCells: A Physically Reconfigurable Cell-composed TouchscreenTouchscreens are the predominant medium for interactions with digital services; however, their current fixed form factor narrows the scope for rich physical interactions by limiting interaction possibilities to a single, planar surface. In this paper we introduce the concept of PickCells, a fully re-configurable device concept composed of cells, that breaks the mould of rigid screens and explores a modular system that affords rich sets of tangible interactions and novel across-device relationships. Through a series of co-design activities -- involving HCI experts and potential end-users of such systems -- we synthesised a design space aimed at inspiring future research, giving researchers and designers a framework in which to explore modular screen interactions. The design space we propose unifies existing works on modular touch surfaces under a general framework and broadens horizons by opening up unexplored spaces providing new interaction possibilities. In this paper, we present the PickCells concept, a design space of modular touch surfaces, and propose a toolkit for quick scenario prototyping.2019AGAlix Goguey et al.Swansea UniversityShape-Changing Interfaces & Soft Robotic MaterialsCustomizable & Personalized ObjectsCHI