Delays in direct teleoperation decouple operator input from robot feedback. We frame this not as a unitary problem but as three facets of operator uncertainty: (1) communication, when commands take effect, (2) trajectory, how inputs map to motion, and (3) environmental, how external factors alter outcomes. We externalized each facet through predictive visualizations: Network, Path, and Envelope. In a controlled study with 24 participants (novices in telerobotics) navigating a simulated robot under a fixed 2.56 s round-trip delay, we compared these visualizations against a delayed-video baseline. Path significantly shortened task time, lowered perceived cognitive load, and reduced reliance on reactive “move-and-wait” behavior. Envelope lowered cognitive load but did not significantly reduce reactive behavior or improve performance, while Network had no measurable effect. These results indicate that predictive support is effective only when trajectory uncertainty is externalized, enabling operators to move from reactive to more proactive control.

Scrolling is ubiquitous in our daily computing experience. We explore how single-handed microgestures can be used for scrolling. Based on an analysis of the basic components necessary for scrolling, we selected 3 microgestures: Tap, Hold and Drag. Considering both rate and position controls, we designed 4 microgesture-based scrolling techniques adapted to these 3 microgestures. We contrasted these 4 techniques in a laboratory experiment with 24 participants who performed 2 tasks: a reciprocal selection task, where participants scrolled the view to reach and select a target; and a counting task, where participants scrolled the view to count image occurrences. Our results suggest that the technique based on Drag microgestures with rate control is the most effective for scrolling operations, regardless of the task. This work demonstrates that microgestures, with their advantages for frequent everyday tasks, offer a promising approach to continuous and efficient scrolling control.

As immersive technologies advance, Mixed Reality Performances (MRP) increasingly integrate them but often face technical challenges that must balance artistic vision and practical constraints.These constraints sometimes lead to unavoidable limitations.The diversity of technologies and artistic goals in MRP prevents a onesize-fits-all solution to such dilemmas.This paper presents a model unifying strategies for addressing compromises between artistic intent and technological feasibility.Using reflexive thematic analysis of a performance-led case study, interviews, and independent case studies, we identify recurring strategies in Mixed Reality experiences with varying constraints.These strategies fall on an axis based on the audience's awareness of limitations and are categorized into five approaches: Avoid, Disguise, Tolerate, Integrate, or Leverage.We argue that this framework helps designers better navigate the limitations inherent in creating MRPs, offering practical pathways to align technological capabilities with creative objectives.

When several people are co-located and immersed in a mixed reality environment, they may feel like they share the virtual environment or not. This feeling of copresence, along with its parent dimensions of social presence and presence, has been mostly studied by relying on subjective measures gathered through questionnaires. As a way to address the drawbacks of this approach, we introduce a protocol to gather behavioral measures in the context of co-located mixed reality. As a pair of participants avoid obstacles moving towards them, their errors, gaze, interpersonal distance, and timing are measured. By combining subjective measures gathered through a questionnaire drawing from previous studies on social presence with behavioral measures, we demonstrate new ways to assess how users experience copresence. We illustrate this protocol by evaluating the effect of visual feedback on collaborators' activity. The results of this experiment suggest the capability of our protocol by revealing the effect of visual feedback on both objective and subjective measures.

Direct manipulation has been established as the main interaction paradigm for Computer-Aided Design (CAD) for decades. It provides fast, incremental, and reversible actions that allow for an iterative process on a visual representation of the result. Despite its numerous advantages, some users prefer a programming-based approach where they describe the 3D model they design with a specific programming language, such as OpenSCAD. It allows users to create complex structured geometries and facilitates abstraction. Unfortunately, most current knowledge about CAD practices only focuses on direct manipulation programs. In this study, we interviewed 20 programming-based CAD users to understand their motivations and challenges. Our findings reveal that this programming-oriented population presents difficulties in the design process in tasks such as 3D spatial understanding, validation and code debugging, creation of organic shapes, and code-view navigation.

We explore the use of vibrotactile haptic cues for representing microgestures. We built a four-axes haptic device for providing vibrotactile cues mapped to all four fingers. We also designed six patterns, inspired by six most commonly studied microgestures. The patterns can be played independently on each axis of the device. We ran an experiment with 36 participants testing three different device locations (fingers, back of the hand, and forearm) for pattern and axis recognition. For all three device locations, participants interpreted the patterns with similar accuracy. We also found that they were better at distinguishing the axes when the device is placed on the fingers. Hand and Forearm device locations remain suitable alternatives but involve a greater trade-off between recognition rate and expressiveness. We report the recognition rates obtained for the different patterns, axes and their combinations per device location. These results per device location are important, as constraints of various kinds, such as hardware, context of use and user activities, influence device location. We discuss this choice of device location by improving literature microgesture-based scenarios with haptic feedback or feedforward.

Parametric Computer-aided design (CAD) enables the creation of reusable models by integrating variables into geometric properties, facilitating customization without a complete redesign. However, creating parametric designs in programming-based CAD presents significant challenges. Users define models in a code editor using a programming language, with the application generating a visual representation in a viewport. This process involves complex programming and arithmetic expressions to describe geometric properties, linking various object properties to create parametric designs. Unfortunately, these applications lack assistance, making the process unnecessarily demanding. We propose a solution that allows users to retrieve parametric expressions from the visual representation for reuse in the code, streamlining the design process. We demonstrated this concept through a proof-of-concept implemented in the programming-based CAD application, OpenSCAD, and conducted an experiment with 11 users. Our findings suggest that this solution could significantly reduce design errors, improve interactivity and engagement in the design process, and lower the entry barrier for newcomers by reducing the mathematical skills typically required in programming-based CAD applications.

Consumer-grade virtual reality (VR) controllers are typically equipped with one vibrotactile actuator, allowing to create simple and non-spatialized tactile sensations through the vibration of the entire controller. Leveraging the funneling effect, an illusion in which multiple vibrations are perceived as a single one, we propose MultiVibes, a VR controller capable of rendering spatialized sensations at different locations on the user’s hand and fingers. The designed prototype includes ten vibrotactile actuators, directly in contact with the skin of the hand, limiting the propagation of vibrations through the controller. We evaluated MultiVibes through two controlled experiments. The first one focused on the ability of users to recognize spatio-temporal patterns, while the second one focused on the impact of MultiVibes on the users’ haptic experience when interacting with virtual objects they can feel. Taken together, the results show that MultiVibes is capable of providing accurate spatialized feedback and that users prefer MultiVibes over recent VR controllers.

When designing virtual embodiment studies, one of the key choices is the nature of the experimental factors, either between-subjects or within-subjects. However, it is well known that each design has ad-vantages and disadvantages in terms of statistical power, sample size requirements and confounding factors. This paper reports a within-subjects experiment with 92 participants comparing self-reported embodiment scores under a visuomotor task with two conditions: synchronous motions and asynchronous motions with a latency of 300 ms. With the gathered data, using a Monte-Carlo method, we created numerous simulations of within- and between-subjects experiments by selecting subsets of the data. In particular, we explored the impact of the number of participants on the replicability of the results from the 92 within-subjects experiment. For the between-subjects simulations, only the first condition for each user was considered to create the simulations. The results showed that while the replicability of the results increased as the number of participants increased for the within-subjects simulations, no matter the number of participants, between-subjects simulations were not able to replicate the initial results. We discuss the potential reasons that could have led to this surprising result and potential methodological practices to mitigate them.

We investigate how users touch arbitrary shapes. First, we performed semi-structured interviews with a fifteen-shape set as prop to identify touch strategies. Results reveal four main potential touch strategies, from which we devised nine mathematical candidate models. We investigate the ability of these models to predict human behaviour in a controlled experiment. We found that the center of a shape’s bounding box best approximates a user’s target location when touching arbitrary shapes. Our findings not only invite designers to use a larger variety of shapes, but can also be used to design touch interaction adapted to user behaviour using our model. As an example, they are likely to be valuable for the creation of applications exposing shapes of various complexities, like drawing applications.

The control of an avatar’s facial expressions in virtual reality is mainly based on the automated recognition and transposition of the user’s facial expressions. These isomorphic techniques are limited to what users can convey with their own face and have recognition issues. To overcome these limitations, non-isomorphic techniques rely on interaction techniques using input devices to control the avatar’s facial expressions. Such techniques need to be designed to quickly and easily select and control an expression, and not disrupt a main task such as talking. We present the design of a set of new non-isomorphic interaction techniques for controlling an avatar facial expression in VR using a standard VR controller. These techniques have been evaluated through two controlled experiments to help designing an interaction technique combining the strengths of each approach. This technique was evaluated in a final ecological study showing it can be used in contexts such as social applications.

Raycasting is the most common target pointing technique in virtual reality environments. However, performance on small and distant targets is impacted by the accuracy of the pointing device and the user's motor skills. Current pointing facilitation techniques are currently only applied in the context of the virtual hand, i.e. for targets within reach. We propose enhancements to Raycasting: filtering the ray, and adding a controllable cursor on the ray to select the nearest target. We describe a series of studies for the design of the visual feedforward, filtering technique, as well as a comparative study between different 3D pointing techniques. Our results show that highlighting the nearest target is one of the most efficient visual feedforward technique. We also show that filtering the ray reduces error rate in a drastic way. Finally we show the benefits of RayCursor compared to Raycasting and another technique from the literature.

Current freehand interactions with large displays rely on point & select as the dominant paradigm. However, constant hand movement in air for pointer navigation leads to hand fatigue quickly. We introduce summon & select, a new model for freehand interaction where, instead of navigating to the control, the user summons it into focus and then manipulates it. Summon & select solves the problems of constant pointer navigation, need for precise selection, and out-of-bounds gestures that plague point & select. We describe the design and conduct two studies to evaluate the design and compare it against point & select in a multi-button selection study. The results show that summon & select is significantly faster and has less physical and mental demand than point & select.

We present a low cost method to measure and characterize the end-to-end latency when using a touch system (tap latency) or an input device equipped with a physical button. Our method relies on a vibration sensor attached to a finger and a photo-diode to detect the screen response. Both are connected to a micro-controller connected to a host computer using a low-latency USB communication protocol in order to combine software and hardware probes to help determine where the latency comes from. We present the operating principle of our method before investigating the main sources of latency in several systems. We show that most of the latency originates from the display side. Our method can help application designers characterize and troubleshoot latency on a wide range of interactive systems.

FlexStylus, a flexible stylus, detects deformation of the barrel as a vector with both a rotational and an absolute value, providing two degrees of freedom with the goal of improving the expressivity of digital art using a stylus device. We outline the construction of the prototype and the principles behind the sensing method, which uses a cluster of four fibre-optic based deformation sensors. We propose interaction techniques using the FlexStylus to improve menu navigation and tool selection. Finally, we describe a study comparing users' ability to match a changing target value using a commercial pressure stylus and the FlexStylus' absolute deformation. When using the FlexStylus, users had a significantly higher accuracy overall. This suggests that deformation may be a useful input method for future work considering stylus augmentation.

We investigate the potential benefits of actuated devices for the desktop workstation which remains the most used environment for daily office works. A formative study reveals that the desktop workstation is not a fixed environment because users manually change the position and the orientation of their devices. Based on these findings, we present the LivingDesktop, an augmented desktop workstation with devices (mouse, keyboard, monitor) capable of moving autonomously. We describe interaction techniques and applications illustrating how actuated desktop workstations can improve ergonomics, foster collaboration, leverage context and reinforce physicality. Finally, the findings of a scenario evaluation are (1) the perceived usefulness of ergonomics and collaboration applications; (2) how the LivingDesktop inspired our participants to elaborate novel accessibility and social applications; (3) the location and user practices should be considered when designed actuated desktop devices.

Smartwatches and activity trackers are becoming prevalent, providing information about health and fitness, and offering personalized progress monitoring. These wearable devices often offer multimodal feedback with embedded visual, audio, and vibrotactile displays. Vibrations are particularly useful when providing discreet feedback, without users having to look at a display or anyone else noticing, thus preserving the flow of the primary activity. Yet, current use of vibrations is limited to basic patterns, since representing more complex information with a single actuator is challenging. Moreover, it is unclear how much the user--s current physical activity may interfere with their understanding of the vibrations. We address both issues through the design and evaluation of ActiVibe, a set of vibrotactile icons designed to represent progress through the values 1 to 10. We demonstrate a recognition rate of over 96% in a laboratory setting using a commercial smartwatch. ActiVibe was also evaluated in situ with 22 participants for a 28-day period. We show that the recognition rate is 88.7% in the wild and give a list of factors that affect the recognition, as well as provide design guidelines for communicating progress via vibrations.

Tactile displays have predominantly been used for information transfer using patterns or as assistive feedback for interactions. With recent advances in hardware for conveying increasingly rich tactile information that mirrors visual information, and the increasing viability of wearables that remain in constant contact with the skin, there is a compelling argument for exploring tactile interactions as rich as visual displays. Direct Manipulation underlies much of the advances in visual interactions. In this work, we introduce the concept of a Direct Manipulation-enabled Tactile display (DMT). We define the concepts of a tactile screen, tactile pixel, tactile pointer, and tactile target which enable tactile pointing, selection and drag & drop. We build a proof of concept tactile display and study its precision limits. We further develop a performance model for DMTs based on a tactile target acquisition study. Finally, we study user performance in a real-world DMT menu application. The results show that users are able to use the application with relative ease and speed.

Hotkeys are an efficient method of selecting commands on a keyboard. However, these shortcuts are often underused by users. We present Métamorphe, a novel keyboard with keys that can be individually raised and lowered to promote hotkeys usage. Métamorphe augments the output of traditional keyboards with haptic and visual feedback, and offers a novel design space for user input on raised keys (e.g., gestures such as squeezing or pushing the sides of a key). We detail the implementation of Métamorphe and discuss design factors. We also report two user studies. The first is a user-defined interface study that shows that the new input vocabulary is usable and useful, and provides insights into the mental models that users associate with raised keys. The second user study shows improved eyes-free selection performance for raised keys as well as the surrounding unraised keys.

This paper presents S-Notebook, a tool that makes it possible to "extend" mobile devices with augmented paper. Paper is used to overcome the physical limitations of mobile devices by offering additional space to annotate digital files and to easily create relationships between them. S-Notebook allows users to link paper annotations or drawings to anchors in digital files without having to learn pre-defined pen gestures. The systems stores meta data such as spatial or temporal location of anchors in the document as well as the zoom level of the view. Tapping on notes with the digital pen make appear the corresponding documents as displayed when the notes were taken. A given piece of augmented paper can contain notes associated to several documents, possibliy at several locations. The annotation space can thus serve as a simple way to relate various pieces of one or several digital documents between them. When the user shares his notes, the piece of paper becomes a tangible token that virtually contains digital information.

Modern information technology allows us to seek out new ways to support the computer use and communication of disabled people. With the aid of new interaction technologies and techniques visually impaired and sighted users can collaborate, for example, in the classroom situations. The main goal of the MICOLE project was to create a software architecture that makes it easier for the developers to create multimodal multi-user applications. The framework is based on interconnected software agents. The hardware used in this study includes VTPlayer Mouse which has two built-in Braille displays, and several haptic devices such as PHANToM Omni, PHANToM Desktop and PHANToM Premium. We also used the SpaceMouse and various audio setups in the applications. In this paper we present a software architecture, a set of software agents, and an example of using the architecture. The example application shown is an electric circuit application that follows the single-user with many devices scenario. The application uses a PHANToM and a VTPlayer Mouse together with visual and audio feedback to make the electric circuits understandable through touch.