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.

UniPad is a face-to-face, digital simulation for use in classroom settings that runs on shared tablets and a wall display. The goal is to encourage students to talk, collaborate and make decisions together in real-time, by switching between working on shared 'small group' devices and a 'whole classroom' public display - instead of working by themselves using their own device. It is intended to improve peer discussion and teacher involvement by focusing and constraining shared attention at different stages of an activity. The domain for this study is finance management. The system was designed using an iterative, participatory design method with expert finance educators and then trialed using an in-the-wild study at a school. The findings show how the set-up helped in facilitating verbal participation in the classroom. We discuss how lightweight, multi-device shared technology systems, such as UniPad, can be designed and used for a range of classroom activities.

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.

There is much potential for supporting collaborative learning with interactive computer simulations in formal education and professional training. A number have been developed for single user and remote interaction. In contrast, our research is concerned with how such learning activities can be designed to fit into co-located large group settings, such as whole classrooms. This paper reports on the iterative design process and two in-the-wild evaluations of the 4Decades game, which was developed for a whole classroom of students to engage with a climate simulation. The system allows students to play and change the rules of the simulation, thereby enabling them to be actively engaged at different levels. The notion of Contributory Simulations is proposed as an instructional model that empowers groups to make informed, critical changes to the underlying scientific model. We discuss how large-group collaboration was supported through constraining an ecology of shared devices and public displays.

A new approach to building modelling software, to support the iterative design of energy efficient buildings, is proposed. The proposal is for the combination of two, previously separate, software types - building design modelling and building performance simulation, along with the development of a third component - a design advisor, into one software tool. This software is intended for use by architectural practices, who may not have access to energy expertise, and who may then struggle to maintain design standards for non-domestic buildings required to satisfy rigorous energy performance regulations. In this paper we describe, through an example, how the three components would work together, by the employment of zone meshes, to visualise, simulate and support with information and advice, the design of a building. The novelty of the method resides in the application of underlying zone meshes for the support of iterative building design. The approach is described, illustrated and future work outlined.

When electronic musicians compose collaboratively, they typically use their own single-user musical controllers. It may, therefore, be useful to develop novel controllers that support collaborative workflows and democratic principles. After describing the design principles for developing such controllers, we present TOUCHtr4ck, a prototype multi-touch system designed to facilitate such democratic relationships. Informal testing has revealed that this approach does facilitate democratic and collaborative music making, and can produce creative musical results.

Buildings account for significant carbon dioxide emissions, both in construction and operation. Governments around the world are setting targets and legislating to reduce the carbon emissions related to the built environment. Challenges presented by increasingly rigorous standards for construction projects will mean a paradigm shift in how new buildings are designed and managed. This will lead to the need for computational modelling and visualization of buildings and their energy performance throughout the life-cycle of the building. This paper briefly outline how the UK government is planning to reduce carbon emissions for new buildings. It discusses the challenges faced by the architectural, construction and building management professions in adjusting to the proposed requirements for low or zero carbon buildings. It then outlines how software tools, including the use of visualization tools, could develop to support the designer, contractor and user.

This paper reports on our experience of investigating the role of software systems in the power blackout that affected parts of the United States and Canada on 14 August 2003. Based on a detailed study of the official report on the blackout, our investigation has aimed to bring out requirements engineering lessons that can inform development practices for dependable software systems. Since the causes of failures are typically rooted in the complex structures of software systems and their world contexts, we have deployed and evaluated a framework that looks beyond the scope of software and into its physical context, directing attention to places in the system structures where failures are likely to occur. We report that (i) Problem Frames were effective in diagnosing the causes of failures and documenting the causes in a schematic and accessible way, and (ii) errors in addressing the concerns of biddable domains, model building problems, and monitoring problems had contributed to the blackout.

Abstract Software development is increasingly concerned with maintaining and extending existing software systems to meet the evolving user requirements. Many of these systems are feature‐rich and are developed incrementally. As structures of existing software systems—in addition to the user requirements—influence the specifications, specifying these systems poses unique challenges. This paper reports on our experience of applying an engineering approach to specifying an evolving feature‐rich television software system. In this approach, features are specified modularly by first fitting their problems to known problem patterns, and then analyzing typical concerns—meaning the potential causes of errors—associated with those patterns. In cases where the existing design poses difficulties when fitting problems to patterns, we transform its structure using known design mechanisms so that the problems fit the patterns. After deriving specifications of individual features, possible interactions between features are detected, before declaratively specifying resolutions to undesired interactions. As the concerns of features and their composition are addressed separately, the specifications derived are modular, thus, providing rich treaceability to their requirements. As well as discussing how features may be specified using natural language, we also show how their descriptions may be formalized using a form of temporal logic called the Event Calculus, and prove their correctness using an off‐the‐shelf tool. Copyright © 2009 John Wiley & Sons, Ltd.

Evolving business needs call for customizable choreographed interactions. However, choreography descriptions do not capture the problem-domain knowledge required to perform the customization effectively. Hence, we propose performing the customization to models of organizational requirements motivating the interaction. To facilitate the derivation of the resulting choreography description, we propose an alignment between conversations and organizational dependencies. We employ the domain knowledge and formal semantics of requirements models to find customization alternatives and reason about them. Using the alignment, we derive constraints on conversations systematically from customized requirements models.

We propose an approach to runtime feature composition and conflict resolution that combines arbitration and contingencies. By arbitration we mean the resolution of conflicts between features using priorities. Contingency means having several specifications per feature, satisfying the same requirement, depending on the current state of the shared resource. Evaluation of our approach shows that combining arbitration and contingencies ensures that in the event of a conflict, requirements of the conflicting features are eventually satisfied.

This paper presents a framework for security requirements elicitation and analysis. The framework is based on constructing a context for the system, representing security requirements as constraints, and developing satisfaction arguments for the security requirements. The system context is described using a problem-oriented notation, then is validated against the security requirements through construction of a satisfaction argument. The satisfaction argument consists of two parts: a formal argument that the system can meet its security requirements and a structured informal argument supporting the assumptions expressed in the formal argument. The construction of the satisfaction argument may fail, revealing either that the security requirement cannot be satisfied in the context or that the context does not contain sufficient information to develop the argument. In this case, designers and architects are asked to provide additional design information to resolve the problems. We evaluate the framework by applying it to a security requirements analysis within an air traffic control technology evaluation project.

Problem frames provide a means of analyzing and decomposing problems. They emphasise the world outside of the computer, helping the developer to focus on the problem domain, instead of drifting into inventing solutions. However, even modestly complex problems can force us into detailed consideration of the architecture of the solution. This is counter to the intention of the problem frames approach, which is to delay consideration of the solution space until a good understanding of the problem is gained. We therefore extend problem frames, allowing architectural structures, services and artifacts to be considered as part of the problem domain. Through a case study, we show how this extension enhances the applicability of problem frames in permitting an architecture-based approach to software development. We conclude that, through our extension, the applicability of problem frames is extended to include domains with existing architectural support.