We present Gestu-Wan, an intelligible gesture guidance system designed to support mid-air gesture-based interaction for walk-up-and-use displays. Although gesture-based interfaces have become more prevalent, there is currently very little uniformity with regard to gesture sets and the way gestures can be executed. This leads to confusion, bad user experiences and users who rather avoid than engage in interaction using mid-air gesturing. Our approach improves the visibility of gesture-based interfaces and facilitates execution of mid-air gestures without prior training. We compare Gestu-Wan with a static gesture guide, which shows that it can help users with both performing complex gestures as well as understanding how the gesture recognizer works.

Previous research has proposed guidelines for creating domain-specific languages for modeling human-machine multimodal dialogs. One of these guidelines suggests the use of multiple levels of abstraction so that the descriptions of multimodal events can be separated from the human-machine dialog model. In line with this guideline, we implemented Hasselt, a domain-specific language that combines textual and visual models, each of them aiming at describing different aspects of the intended dialog system. We conducted a user study to measure whether the proposed language provides benefits over equivalent event-callback code. During the user study participants had to modify the Hasselt models and the equivalent C# code. The completion times obtained for C# were on average shorter, although the difference was not statiscally significant. Subjective responses were collected using standardized questionnaires and an interview, which both indicated that participants saw value in the proposed models. We provide possible explanations for the results and discuss some lessons learned regarding the design of the empirical study.

Nonverbal and unconscious behaviour is an important component of daily human-human interaction. This is especially true in situations such as public speaking, job interviews or information sensitive conversations, where researchers have shown that an increased awareness of one's behaviour can improve the outcome of the interaction. With wearable technology, such as Google Glass, we now have the opportunity to augment social interactions and provide realtime feedback on one's behaviour in an unobtrusive way. In this paper we present Logue, a system that provides realtime feedback on the presenters' openness, body energy and speech rate during public speaking. The system analyses the user's nonverbal behaviour using social signal processing techniques and gives visual feedback on a head-mounted display. We conducted two user studies with a staged and a real presentation scenario which yielded that Logue's feedback was perceived helpful and had a positive impact on the speaker's performance.

Empathic communication allows individuals to perceive and understand the feeling and emotion of the person with whom they are interacting. This could be particularly important during remote collaboration (such as remote assistance or distance learning) to enhance the social and emotional understanding of geographically distributed partners. However, supporting awareness in remote collaboration is very challenging especially when the interaction with the remote parties results in less information that can be communicated than in a physical interaction. We explore the effect of visualization using physiological cues that allow users to interpret emotional behaviors of remote parties with whom they are interacting in real time. The proposed visual representation allows users to infer emotional patterns from physiological cues that can potentially influence their communication approach toward a more aggressive style or maintain passive and peaceful interaction. We conducted a study involving participants who were paired up for a collaborative assessment task, interacting via voice only, videoconference, or a visual representation of the physiological measurements. Participants perceived the usage of our visual representation with higher group cohesiveness than using voice-only interaction. Further analysis shows that the visual representation significantly increases the positive affect score (i.e., participants are perceived to be more alert and demonstrate less distress) during remote collaboration. We discuss the possibilities of the proposed visual representation to support empathic communication during remote collaboration, and the benefits to the remote partners of having positive affect and group cohesiveness.

The misalignment between the timeframe of systems and that of their users can cause problems, especially when the system relies on implicit interaction. It makes it hard for users to understand what is happening and leaves them little chance to intervene. This paper introduces the design concept of slow-motion feedback, which can help to address this issue. A definition is provided, together with an overview of existing applications of this technique.

We present a new interaction space for wearables by integrating interactive elements, in the form of buttons, into outdoor clothing, specifically jackets and coats. Interactive buttons, or "iButtons", allow users to perform specific tasks using subtle, inconspicuous gestures. They are intended for outdoor settings, where reaching for a mobile phone or an other device may not be convenient or appropriate. Different types of buttons serve dedicated functions, and appropriate placement of these buttons make them easily accessible, without requiring visual contact. By adding context sensitivity, these buttons can also be repurposed to fit other functions. By linking multiple buttons, it is possible to create workflows for specific tasks. We provide a description of an initial iButton design space and highlight some scenarios to illustrate the envisioned usage of interactive buttons.

Paddle is a highly deformable mobile device that leverages engineering principles from the design of the Rubik's Magic, a folding plate puzzle. The various transformations supported by Paddle bridges the gap between differently sized mobile devices available nowadays, such as phones, armbands, tablets and game controllers. Besides this, Paddle can be transformed to different physical controls in only a few steps, such as peeking options, a ring to scroll through lists and a book-like form factor to leaf through pages. These special-purpose physical controls have the advantage of providing clear physical affordances and exploiting people's innate abilities for manipulating objects in the real world. We investigated the benefits of these interaction techniques in detail in [1]. In contrast to traditional touch screens, physical controls are usually less flexible and therefore less suitable for mobile settings. Paddle, shows how mobile devices can be designed to bring physical controls to mobile devices and thus combine the flexibility of touch screens with the physical qualities that real world controls provide. Our current prototype is tracked with an optical tracking system and uses a projector to provide visual output. In the future, we envision devices similar to Paddle that are entirely self-contained, using tiny integrated displays.