This article presents a video-based field study of the Reactable, a tabletop tangible user interface (TUI) for music performance, in a hands-on science centre. The goal was to investigate visitors’ social interactions in a public setting. We describe liminality and cross-group interaction, both synchronous with fluid transitions and overlaps in use between groups and asynchronous. Our findings indicate the importance of: (i) facilitating smooth transitions and overlaps between groups and (ii) supporting not only synchronous but also asynchronous group interaction. We discuss the lessons learned on how best to enable liminal situations in the design of interactive tabletops and TUIs for social interaction and particularly collaborative tangible music in public museum settings.

This paper explores the potential benefits of using similarity-based two-dimensional classifications and their corresponding GUIs, for drum samples retrieval in a creativity-oriented context. Preliminary user studies with professional electronic music producers point up the frustration and laboriousness of finding suitable drum samples in the increasingly large libraries of sounds available, and suggest the need for alternative interfaces and approaches. To address this issue, two novel spatial visualizations (respectively organized by name and by timbre-similarity) are designed as potential alternatives to the traditional 1D list-based browsers. These visualizations are implemented and compared in a music creation task, in terms of both the exploration experience and the resulting production quality, within a system for drum kit configuration. Our study shows that spatial visualizations do improve the overall exploration experience, and reveals the potential of similarity-based arrangements for the support of creative processes.

In this article, we evaluateb-Reactable, a digital music instrument that combines implicit physiology-based interaction through EEG and ECG, and explicit gestural interaction for sound generation and control. This multimodality is embodied in tangible objects namedphysiopucks,which are driven by biosignals. We hypothesize that multimodality increases users’ motivation in a musical task, compared to the use of a gesture-only tabletop system (the Reactable). We compared motivational aspects in dyads collaborating in three experimental groups (N = 56): the Physio group (one physiology- and one gesture-based user), the Sham group (one prerecorded physiology- and one gesture-based user), and the Control group (two gesture users). Between-group comparisons showed that motivation dimensions of Confidence and Satisfaction were higher inb-Reactablethan in the gesture-only tangible interface, and that fake physiology-based feedback significantly reduced these effects. Our study also shows the potential of combined implicit and explicit interaction modes in multiuser HCI scenarios.

Public displays and projections are becoming increasingly available in various informal urban settings. However, their potential impact on informing and engaging citizens on relevant issues has still been largely unexplored. In this paper, we show that visualizations displayed in public settings are able to increase social awareness and discourse by exposing underlying patterns in data that is submitted by citizens. We thus introduce the design and evaluation of Reveal-it!, a public, interactive projection that facilitates the comparison of the energy consumptions of individuals and communities. Our in-the-wild deployment in three distinct physical locations provided insights into: 1) how people responded to this form of display in different contexts; 2) how it influenced people's perception and discussion of individual and communal data; and 3) the implications for a public visualization as a tool for increasing awareness and discourse. We conclude by discussing emerging participant behaviors, as well as some challenges involved in facilitating a socially motivated crowd-sourced visualization in the public context.

Multi-touch technologies have been increasing its popularity in the last decade. Nowadays we can find a plethora of devices that includes this technology: tablets, smartphones or even in desktop computers. In parallel tangible tabletop surfaces started to appear in the global market with devices such as Reactable. What all this devices have in common is its programming cycle often time consuming and hard to prototype.

While the HCI community has been putting a lot of effort on creating physical interfaces for collaboration, studying multi-user interaction dynamics and creating specific applications to support (and test) this kind of phenomena, it has not addressed the problems implied in having multiple applications sharing the same interactive space. Having an ecology of rich interactive programs sharing the same interfaces poses questions on how to deal with interaction ambiguity in a cross-application way and still allow different programmers the freedom to program rich unconstrained interaction experiences.

There has been little research on how interactions with tabletop and Tangible User Interfaces (TUIs) by groups of users change over time. In this article, we investigate the challenges and opportunities of a tabletop tangible interface based on constructive building blocks. We describe a long-term lab study of groups of expert musicians improvising with the Reactable, a commercial tabletop TUI for music performance. We examine interaction, focusing on interface , tangible , musical, and social phenomena. Our findings reveal a practice-based learning between peers in situated contexts, and new forms of participation, all of which is facilitated by the Reactable's tangible interface, if compared to traditional musical ensembles. We summarise our findings as a set of design considerations and conclude that construction processes on interactive tabletops support learning by doing and peer learning, which can inform constructivist approaches to learning with technology.

Creativity is a relevant characteristic for people's development as it facilitates the generation of new ideas and innovation processes. Although technology has played an important role on creativity stimulation, it still needs to be explored for a better understanding and support in the context of information and communication technologies. In this paper a basic creativity assessment model is presented and an empirical study has been conducted whose aim is to get insight into whether an interactive surface as base technology for collaborative creative tasks is promising in terms of both collaboration and creativity traits. In the study two tabletop-based platforms (a digitally-augmented, and a physical-only without computer mediation) were involved to solve a problem consisting of creating Rube-Goldberg machines. From these experiments, we have observed that in terms of creativity traits, interactive surfaces seem promising as groups working in the digital platform showed significantly more performance in fluency of thinking, were more motivated, and novelty was found near to significance. Also some issues related to collaboration and interaction were analyzed. In particular, the co-operation, the retrial fine adjustment, and the dominance showed that the properties of an interactive surface tabletop suits better for facilitating the sharing of objects and participation in conditions of co-operation by co-located participants.

Since commercial musical recordings became available about a century ago and until very recently, they had always been distributed by means of a physical support. Nowadays that record companies have ultimately started to distribute over the Internet, music does not use physical space anymore, and we can now store amazingly large collection in our computers or portable players. But this etherealness does not come without some drawbacks, such as browsing by the covers or organizing and grouping elements or collections.In this paper we propose a system in which files (intangible) become physical objects again, thus recovering part of the mysticism related with vinyls or compact discs, without loosing most of the benefits inherent to digital data, and applying at the same time some advantages that tangible and tabletop interfaces can offer. Complementarily, and from a more agnostic perspective, this paper also starts to explore on the tangible manipulation of sets or collections of items.

Tangible interactions on horizontal surfaces are increasingly relevant for collaborative applications, embodied interaction, musical performance, and interaction with 3D information. This unique studio opportunity introduces approaches to developing applications on four related platforms: the Reactable: a musical tabletop, and its companion fiducial tracking system reacTIVision, Microsoft Surface: a commercial multi-touch table, MemTable: a large interactive tabletop, and Relief: a responsive 3D surface. It will focus on the unique affordances of multi-input and multi-user event handling shared and afforded by each of the four platforms. Participants will work in small groups within some simplified code templates to develop a small applications focused on co-located input by multiple people, combining the use of tangible objects and touch input.

In recent years we have seen a proliferation of musical tables. Believing that this is not just the result of a tabletop trend, in this paper we first discuss several of the reasons for which live music performance and HCI in general, and musical instruments and tabletop interfaces in particular, can lead to a fertile two-way cross-pollination that can equally benefit both fields. After that, we present the reac Table, a musical instrument based on a tabletop interface that exemplifies several of these potential achievements.