Rapid prototyping of ubiquitous computing environments

Tese de doutoramento em InformáticaUbiquitous computing raises new usability challenges that cut across design and development. We are particularly interested in environments enhanced with sensors, public displays and personal devices. How can prototypes be used to explore the users' mobility and interaction, both explicitly and implicitly, to access services within these environments? Because of the potential cost of development and design failure, these systems must be explored using early assessment techniques and versions of the systems that could disrupt if deployed in the target environment. These techniques are required to evaluate alternative solutions before making the decision to deploy the system on location. This is crucial for a successful development, that anticipates potential user problems, and reduces the cost of redesign. This thesis reports on the development of a framework for the rapid prototyping and analysis of ubiquitous computing environments that facilitates the evaluation of design alternatives. It describes APEX, a framework that brings together an existing 3D Application Server with a modelling tool. APEX-based prototypes enable users to navigate a virtual world simulation of the envisaged ubiquitous environment. By this means users can experience many of the features of the proposed design. Prototypes and their simulations are generated in the framework to help the developer understand how the user might experience the system. These are supported through three different layers: a simulation layer (using a 3D Application Server); a modelling layer (using a modelling tool) and a physical layer (using external devices and real users). APEX allows the developer to move between these layers to evaluate different features. It supports exploration of user experience through observation of how users might behave with the system as well as enabling exhaustive analysis based on models. The models support checking of properties based on patterns. These patterns are based on ones that have been used successfully in interactive system analysis in other contexts. They help the analyst to generate and verify relevant properties. Where these properties fail then scenarios suggested by the failure provide an important aid to redesign.A computação ubíqua levanta novos desafios de usabilidade transversais ao seu desenvolvimento e design. Estamos particularmente interessados em ambientes enriquecidos com sensores, ecrãs públicos e dispositivos pessoais e em saber como podem ser utilizados protótipos na exploração da mobilidade e interação, implícita e explicita, dos utilizadores de forma a acederem a serviços desses ambientes. Devido às potenciais falhas do design proposto e aos elevados custos associados ao seu desenvolvimento, as características destes sistemas devem ser exploradas utilizando versões preliminares dos mesmos dado que estes podem vir a falhar quando implementados no destino, tornando a sua utilização inaceitável. Essas técnicas são necessárias por forma a avaliar soluções alternativas antes de decidir implementar o sistema fisicamente. Isto é crucial para um desenvolvimento com sucesso que antecipe potencias problemas do utilizador e reduza os custos de redesign. Esta tese descreve o desenvolvimento de uma ferramenta para a prototipagem rápida e análise de ambientes de computação ubíqua como suporte à avaliação de designs alternativos. É apresentado a APEX, uma plataforma que junta um servidor de aplicações 3D com uma ferramenta de modelação. Os protótipos baseados na APEX permitem aos seus utilizadores finais navegarem numa simulação 3D do ambiente ubíquo projetado. Desta forma muitas das características do design proposto podem ser experienciadas pelos utilizadores. Os protótipos e respetivas simulações são gerados na plataforma para ajudar os designers/developers a entender como é que os utilizadores podem experienciar o sistema. Os protótipos são suportadas através de três camadas: a camada de simulação (utilizando um servidor de aplicações 3D); a camada de modelação (utilizando uma ferramenta de modelação) e uma camada física (utilizando dispositivos externos e utilizadores reais). A plataforma possibilita aos designers/ developers moverem-se entre estas camadas de forma a avaliar diferentes características do sistema, desde a experiencia do utilizador até ao seu comportamento através de uma analise exaustiva do sistema ubíquo baseada em modelos. Os modelos suportam a verificação de propriedades baseadas em padrões. Estes padrões são baseados em padrões existentes e já utilizados com sucesso, noutros contextos, na análise de sistemas interativos. Eles auxiliam a geração e verificação de propriedades relevantes. O local onde estas propriedade falham sugere um cenário de falha que fornece uma ajuda importante no redesign do sistema.ERDF through the Programme COMPETE and by the Portuguese Government through FCT - Foundation for Science and Technology, project PTDC/EIA-EIA/116069/2009 and by FCT, under the grant SFRH/BD/41179/2007

Rapid prototyping of ubiquitous computing environments

Ubiquitous computing raises new usability challenges that cut across design and development. We are particularly interested in environments enhanced with sensors, public displays and personal devices. How can prototypes be used to explore the users' mobility and interaction, both explicitly and implicitly, to access services within these environments? Because of the potential cost of development and design failure, these systems must be explored using early assessment techniques and versions of the systems that could disrupt if deployed in the target environment. These techniques are required to evaluate alternative solutions before making the decision to deploy the system on location. This is crucial for a successful development, that anticipates potential user problems, and reduces the cost of redesign. This thesis reports on the development of a framework for the rapid prototyping and analysis of ubiquitous computing environments that facilitates the evaluation of design alternatives. It describes APEX, a framework that brings together an existing 3D Application Server with a modelling tool. APEX-based prototypes enable users to navigate a virtual world simulation of the envisaged ubiquitous environment. By this means users can experience many of the features of the proposed design. Prototypes and their simulations are generated in the framework to help the developer understand how the user might experience the system. These are supported through three different layers: a simulation layer (using a 3D Application Server); a modelling layer (using a modelling tool) and a physical layer (using external devices and real users). APEX allows the developer to move between these layers to evaluate different features. It supports exploration of user experience through observation of how users might behave with the system as well as enabling exhaustive analysis based on models. The models support checking of properties based on patterns. These patterns are based on ones that have been used successfully in interactive system analysis in other contexts. They help the analyst to generate and verify relevant properties. Where these properties fail then scenarios suggested by the failure provide an important aid to redesign.Fundação para a Ciência e Tecnologi

Structural usability techniques for dependable HCI.

Since their invention in the middle of the twentieth century, interactive computerised systems have become more and more common to the point of ubiquity. While formal techniques have developed as tools for understanding and proving things about the behaviour of computerised systems, those that involve interaction with human users present some particular challenges which are less well addressed by traditional formal methods. There is an under-explored space where interaction and the high assurances provided by formal approaches meet. This thesis presents two techniques which fit into this space, and which can be used to automatically build and analyse formal models of the interaction behaviour of existing systems. Model discovery is a technique for building a state space-based formal model of the interaction behaviour of a running system. The approach systematically and exhaustively simulates the actions of a user of the system; this is a dynamic analysis technique which requires tight integration with the running system and (in practice) its codebase but which, when set up, can proceed entirely automatically. Theorem discovery is a technique for analysing a state space-based formal model of the interaction behaviour of a system, looking for strings of user actions that have equivalent effects across all states of the system. The approach systematically computes and compares the effects of ever-longer strings of actions, though insights can also arise from strings that are almost equivalent, and also from considering the meaning of sets of such equivalences. The thesis introduces and exemplifies each technique, considers how they may be used together, and demonstrates their utility and novelty, with case studies

Social network analysis and interactive device design analysis

What methods can we use to help understand why users adopt certain use strategies, and how can we evaluate designs to anticipate and perhaps positively modify how users are likely to behave? This paper proposes taking advantage of social network analysis (SNA) to identify features of interaction. There are plausible reasons why SNA should be relevant to interaction programming and design, but we also show that SNA has promise, identifies and explains interesting use phenomena, and can be used effectively on conventionally-programmed interactive devices. Social network analysis is a very rich field, practically and theoretically, and many further forms of application and analysis beyond the promising examples explored in this paper are possible