International audience

Designing vibrotactile experiences collaboratively requires communicating using multiple senses. This is challenging in remote scenarios as designers need to effectively express and communicate their intention while iteratively building and refining experiences, ideally in real-time. We formulate design considerations for collaborative haptic design tools, and propose CollabJam, a collaborative prototyping suite enabling remote synchronous design of vibrotactile experiences for on-body applications. We first outline Collab-Jam's features and present a technical evaluation. Second, we use CollabJam to understand communication and design patterns used during haptic experience design. We performed an in-depth design evaluation spanning four sessions in which four pairs of participants designed and reviewed vibrotactile experiences remotely. A qualitative content analysis revealed how multi-sensory communication is essential to convey ideas, how stimulating the tactile sense can interfere with personal boundaries, and how freely placing actuators on the skin can provide both benefits and challenges.

This article tackles two challenges of the empirical evaluation of interaction techniques that rely on user memory, such as hotkeys, here coined Recall-based interaction techniques (RBITs): (1) the lack of guidance to design the associated study protocols, and (2) the difficulty of comparing evaluations performed with different protocols. To address these challenges, we propose a model-based evaluation of RBITs. This approach relies on a computational model of human memory to (1) predict the informativeness of a particular protocol through the variance of the estimated parameters (Fisher Information) (2) compare RBITs recall performance based on the inferred parameters rather than behavioral statistics, which has the advantage of being independent of the study protocol. We also release a Python library implementing our approach to aid researchers in producing more robust and meaningful comparisons of RBITs.

Visual content must be labeled to facilitate navigation and retrieval, or provide ground truth data for supervised machine learning approaches. The efficiency of labeling techniques is crucial to produce numerous qualitative labels, but existing techniques remain sparsely evaluated. We systematically evaluate the efficiency of tagging and browsing tasks in relation to the number of images displayed, interaction modes, and the image visual complexity. Tagging consists in focusing on a single image to assign multiple labels (image-oriented strategy), and browsing in focusing on a single label to assign to multiple images (label-oriented strategy). In a first experiment, we focus on the nudges inducing participants to adopt one of the strategies (n=18). In a second experiment, we evaluate the efficiency of the strategies (n=24). Results suggest an image-oriented strategy (tagging task) leads to shorter annotation times, especially for complex images, and participants tend to adopt it regardless of the conditions they face.

We present TactJam, an end-to-end suite for creating and sharing low fidelity prototypes of on-body vibrotactile feedback. With TactJam, designers can create, record and share vibrotactile patterns online. This opens up new ways of collaboratively designing vibrotactile patterns both in collocated as well as in remote settings. We evaluate TactJam in a two-part distributed online workshop, exploring the design of on-body tactons. Participants were able to successfully use TactJam to learn about tacton design. We present an overview of mappings between tactons and their associated concepts before comparing the results of tactons created using solely a GUI and tactons created through experimenting with placements directly on the body. Conducting both parts of the workshop separately highlighted the importance of designing directly with bodies: less implicit assumptions were made, and designs were guided by personal experience. We reflect on these results and close on deliberations for the future development of TactJam.

We are surrounded by sensing devices. We are accustomed to them, appreciate their benefits, and even create affective bonds and might neglect the implications they might have for our daily life. By presenting Eyecam, an anthropomorphic webcam mimicking a human eye, we challenge conventional relationships with ubiquitous sensing devices and call to re-think how sensing devices might appear and behave. Inspired by critical design, Eyecam is an exaggeration of a familiar sensing device which allows for critical reflections on its perceived functionalities and its impact on human-human and human-device relations. We identify 5 different roles Eyecam can take: Mediator, Observer, Mirror, Presence, and Agent. Contributing design fictions and thinking prompts, we allow for articulation on privacy awareness and intrusion, affect in mediated communication, agency and self-perception along with speculation on potential futures. We envision this work to contribute to a bold and responsible design of ubiquitous sensing devices.

Today’s typical input device is flat, rigid and made of glass. However, advances in sensing technology and interaction design suggest thinking about input on other surface, including soft materials. While touching rigid and soft materials might feel similar, they clearly feel different when pressure is applied to them. Yet, to date, studies only investigated force input on rigid surfaces. We present a first systematic evaluation of the effects of compliance on force input. Results of a visual targeting task for three levels of softness indicate that high force levels appear more demanding for soft surfaces, but that performance is otherwise similar. Performance remained very high (∼ 5% for 20 force levels) regardless of the compliance, suggesting force input was underestimated so far. We infer implications for the design of force input on soft surfaces and conclude that interaction models used on rigid surfaces might be used on soft surfaces.

In traditional body-art, designs are adjusted to the body as they are applied, enabling creative improvisation and exploration. Conventional design and fabrication methods of epidermal interfaces, however, separate these steps. With BodyStylus we present the first computer-assisted approach for on-body design and fabrication of epidermal interfaces. Inspired by traditional techniques, we propose a hand-held tool that augments freehand inking with digital support: projected in-situ guidance assists creating valid on-body circuits and aesthetic ornaments that align with the human bodyscape, while pro-active switching between inking and non-inking creates error preventing constraints. We contribute BodyStylus’s design rationale and interaction concept along with an interactive prototype that uses self-sintering conductive ink. Results of two focus group explorations showed that guidance was more appreciated by artists, while constraints appeared more useful to engineers, and that working on the body inspired critical reflection on the relationship between bodyscape, interaction, and designs.

Using microgestures, prior work has successfully enabled gestural interactions while holding objects. Yet, these existing methods are prone to false activations caused by natural finger movements while holding or manipulating the object. We address this issue with SoloFinger, a novel concept that allows design of microgestures that are robust against movements that naturally occur during primary activities. Using a data-driven approach, we establish that single-finger movements are rare in everyday hand-object actions and infer a single-finger input technique resilient to false activation. We demonstrate this concept’s robustness using a white-box classifier on a pre-existing dataset comprising 36 everyday hand-object actions. Our findings validate that simple SoloFinger gestures can relieve the need for complex finger configurations or delimiting gestures and that SoloFinger is applicable to diverse hand-object actions. Finally, we demonstrate SoloFinger’s high performance on commodity hardware using random forest classifiers.

Tactons are vibrotactile patterns used to convey information. Conventionally, a small set of tactons is used on mobile phone or wearables to notify users of messages or emails received. However, tactons have multiple characteristics that one can vary to design a multitude of vibrotactile patterns. In addition, one can place vibrotactile actuators on different body areas to leverage the spatial dimension and the varying skin sensitivity across the body. Prior work proposed methods to design tactons based on musical or engineering knowledge, but hands-on methods remain scarce. For this studio, we adopt a hands-on approach for composing tactons. We leverage a simple instrument-like device that consists of vibrotactile actuators connected to dedicated buttons for designing tactons. While pressing a button, the corresponding actuator vibrates. Users can vary several characteristics of the tactons (e.g., duration and amplitude), and experience them in real time during the design process by placing the actuators on the body. These tactons can then be shared with other participants of the studio. Our goal with this studio is to observe users compose tactons collaboratively using a hands-on device, and better understand how they lay out the vibrotactile actuators on their body and what differences these layouts make in the tactile experience.

Effective haptic feedback in virtual reality (VR) is an essential element for creating convincing immersive experiences. To design such feedback, state-of-the-art VR setups provide APIs for programmatically generating controller vibration patterns. While tools for designing vibrotactile feedback keep evolving, they often require expert knowledge and rarely support direct manipulation methods for mapping feedback to user interactions within the VR environment. To address these challenges, we contribute a novel concept called Weirding Haptics, that supports fast-prototyping by leveraging the user’s voice to design such feedback while manipulating virtual objects in-situ. Through a pilot study (N = 9) focusing on how tactile experiences are vocalized during object manipulation, we identify spatio-temporal mappings and supporting features needed to produce intended vocalizations. To study our concept, we built a VR design tool informed by the results of the pilot study. This tool enables users to design tactile experiences using their voice while manipulating objects, provides a set of modifiers for fine-tuning the created experiences in VR, and allows to rapidly compare various experiences by feeling them. Results from a validation study (N = 8) show that novice hapticians can vocalize experiences and refine their designs with the fine-tuning modifiers to match their intentions. We conclude our work by discussing uncovered design implications for direct manipulation and vocalization of vibrotactile feedback in immersive virtual environments.

We present a method for enabling arbitrary textiles to sense pressure and deformation: In-situ polymerization supports integration of piezoresistive properties at the material level, preserving a textile's haptic and mechanical characteristics. We demonstrate how to enhance a wide set of fabrics and yarns using only readily available tools. To further support customisation by the designer, we present methods for patterning, as needed to create circuits and sensors, and demonstrate how to combine areas of different conductance in one material. Technical evaluation results demonstrate the performance of sensors created using our method is comparable to off-the-shelf piezoresistive textiles. As application examples, we demonstrate rapid manufacturing of on-body interfaces, tie-dyed motion-capture clothing, and zippers that act as potentiometers.

Many features of materials can be experienced through tactile cues, even using one's feet. For example, one can easily distinguish between moss and stone without looking at the ground. However, this type of material experience is largely not supported in AR and VR applications. We present bARefoot, a prototype shoe providing tactile impulses tightly coupled to motor actions. This enables generating virtual material experiences such as compliance, elasticity, or friction. To explore the parameter space of such sensorimotor coupled vibrations, we present a design tool enabling rapid design of virtual materials. We report initial explorations to increase understanding of how parameters can be optimized for generating compliance, and to examine the effect of dynamic parameters on material experiences. Finally, we present a series of use cases that demonstrate the potential of bARefoot for VR and AR.

Supporting many gestures on small surfaces allows users to interact remotely with complex environments such as smart homes, large remote displays, or virtual reality environments, and switching between them (e.g., AR setup in a smart home). Providing eyes-free gestures in these contexts is important as this avoids disrupting the user's visual attention. However, very few techniques enable large sets of commands on small wearable devices supporting the user's mobility and even less provide eyes-free interaction. We present Side-Crossing Menus (SCM), a gestural technique enabling large sets of gestures on %small interactive surfaces like a smartwatch. Contrary to most gestural techniques, SCM relies on broad and shallow menus that favor small and rapid gestures. We demonstrate with a first experiment that users can efficiently perform these gestures eyes-free aided with tactile cues; 95% accuracy after training 20 minutes on a representative set of 30 gestures among 172. In a second experiment, we focus on the learning of SCM gestures and do not observe significant differences with conventional Multi-stroke Marking Menus in gesture accuracy and recall rate. As both techniques utilize contrasting menu structures, our results indicate that SCM is a compelling alternative for enhancing the input capabilities of small surfaces.

Previous studies have shown that spatial memory and semantic aids can help users learn and remember gestural commands. Using the body as a support to combine both dimensions has therefore been proposed, but no formal evaluations have yet been reported. In this paper, we compare an on-body interaction technique (BodyLoci) to mid-air Marking menus in a virtual reality context. We consider three levels of semantic aids: no aid, story-making, and story-making with background images. Our results show important improvement when story-making is used, especially for Marking menus (28.5% better retention). Both techniques performed similarly without semantic aids, but Marking menus outperformed BodyLoci when using them (17.3% better retention). While our study does not show a benefit in using body support, it suggests that inducing users to leverage simple learning techniques, such as story-making, can substantially improve recall, and thus make it easier to master gestural techniques. We also analyze the strategies used by the participants for creating mnemonics to provide guidelines for future work.

Various techniques have been proposed to faster command selection. Many of them either rely on directional gestures (e.g. Marking menus) or pointing gestures using a spatially-stable arrangement of items (e.g. FastTap). Both types of techniques are known to leverage memorization, but not necessarily for the same reasons. In this paper, we investigate whether using directions or positions affects gesture learning. Our study shows that, while recall rates are not significantly different, participants used the novice mode more often and spent more time while learning commands with directional gestures, and they also reported more physical and mental efforts. Moreover, this study also highlights the importance of semantic relationships between gestural commands and reports on the memorization strategies that were elaborated by the participants.

We present MarkPad, a novel interaction technique taking advantage of the touchpad. MarkPad allows creating a large number of size-dependent gestural shortcuts that can be spatially organized as desired by the user. It relies on the idea of using visual or tactile marks on the touchpad or a combination of them. Gestures start from a mark on the border and end on another mark anywhere. MarkPad does not conflict with standard interactions and provides a novice mode that acts as a rehearsal of the expert mode. A first study showed that an accuracy of 95% could be achieved for a dense configuration of tactile and/or visual marks allowing many gestures. Performance was 5% lower in a second study where the marks were only on the borders. A last study showed that borders are rarely used, even when the users are unaware of the technique. Finally, we present a working prototype and briefly report on how it was used by two users for a few months.