Development of virtual network computing (VNC) environment for networking and enhancing user experience

Virtual Network Computing (VNC) is a thin client developed by Real VNC Ltd, Formerly of Olivetti Research Ltd/AT&T labs Cambridge and can be used as a collaborative environment, therefore it has been chosen as the basis of this research study. The purpose of this thesis is to investigate and develop a VNC based environment over the network and to improve the users’ Quality of Experience (QoE) of using VNC between networked groups by the incorporation of videoconferencing with VNC and enhancing QoE in Mobile environments where the network status is far from ideal and is prone to disconnection. This thesis investigates the operation of VNC in different environments and scenarios such as wireless environments by investigating user and device mobility and ways to sustain their seamless connection when in motion. As part of the study I also researched all groups that implement VNC like universities, research groups and laboratories and virtual laboratories. In addition to that I identified the successful features and security measures in VNC in order to create a secure environment. This was achieved by pinpointing the points of strength and weakness in VNC as opposed to popular thin clients and remote control applications and analysing VNC according to conforming to several security measures. Furthermore, it is reasonable to say that the success of any scheme that attempts to deliver desirable levels of Quality of Service (QoS) of an effective application for the future Internet must be based, not only on the progress of technology, but on usersʹ requirements. For instance, a collaborative environment has not yet reached the desired expectation of its users since it is not capable of handling any unexpected events which can result from a sudden disconnection of a nomadic user engaged in an ongoing collaborative session; this is consequently associated with breaking the social dynamics of the group collaborating in the session. Therefore, I have concluded that knowing the social dynamics of application’s users as a group and their requirements and expectations of a successful experience can lead an application designer to exploit technology to autonomously support the initiating and maintaining of social interaction. Moreover, I was able to successfully develop a VNC based environment for networked groups that facilitates the administration of different remote VNC sessions. In addition to a prototype that uses videoconferencing in parallel to VNC to provide a better user’s QoE of VNC. The last part of the thesis was concerned with designing a framework to improve and assess QoE of all users in a collaborative environment where it can be especially applied in the presence of nomadic clients with their much frequent disconnections. I have designed a conceptual algorithm called Improved Collaborative Quality of Experience (IC‐QoE), an algorithm that aims to eliminate frustration and improve QoE of users in a collaborative session in the case of disconnections and examined its use and benefits in real world scenarios such as research teams and implemented a prototype to present the concepts of this algorithm. Finally, I have designed a framework to suggest ways to evaluate this algorithm

Haptic augmentation of the cursor: transforming virtual actions into physical actions

This thesis demonstrates, through the exploration of two very different examples, the general claim that haptic feedback relating to a user's representation in a computer system (typically a cursor) can lead to increases in objective performance and subjective experience. Design guidelines covering each of these two topics are also presented, to ensure that the research described here can be readily adopted by other researchers, designers and system developers. The first topic to be investigated was desktop user interfaces. This thesis describes the design of a variety of different forms of haptic feedback for use with number of different Graphical User Interface (GUI) widgets, or widget groups. Two empirical evaluations of these designs are also described in some depth. The results of these studies indicate that although haptic feedback can provide improvements in objective performance, it can also reduce performance and increase subjective workload if inappropriately applied. From these results, and from the previous literature, detailed guidelines were drawn up covering the addition of haptic feedback to GUIs. The goal of these guidelines is to support the creation of performance-enhancing haptic feedback. The second topic examined was communication in interactive collaborative systems. The design of a suite of haptic communication is presented in detail, before two studies investigating different aspects of its use. The first study focuses on the subjective influence of the haptic communication as a whole, while the second is a more thorough look at one particular form of the feedback and includes objective measurements. The combined results of these studies indicate that haptic feedback has a valuable potential for increasing the quality of a user's subjective experience. Observations from these studies also reveal insights into the role of haptic feedback in communication. A set of guidelines summing up this research and the previous literature relevant to this topic are then presented. As research on this domain is in its infancy, the goal of these guidelines is to concisely present the main issues and potential benefits that respectively restrict and drive this work

Towards self-optimizing frameworks for collaborative systems

Two important performance metrics in collaborative systems are local and remote response times. For certain classes of applications, it is possible to meet response time requirements better than existing systems through a new system without requiring hardware, network, or user-interface changes. This self-optimizing system improves response times by automatically making runtime adjustments to three aspects of a collaborative application. One of these aspects is the collaboration architecture. Previous work has shown that dynamically switching architectures at runtime can improve response times; however, no previous work performs the switch automatically. The thesis shows that (a) another important performance parameter is whether multicast or unicast is used to transmit commands, and (b) response times can be noticeably better with multicast than with unicast when transmission costs are high. Traditional architectures, however, support only unicast - a computer that processes input commands must also transmit commands to all other computers. To support multicast, a new bi-architecture model of collaborative systems is introduced in which two separate architectures govern the processing and transmission tasks that each computer must perform. The thesis also shows that another important performance aspect is the order in which a computer performs these tasks. These tasks can be scheduled sequentially or concurrently on a single-core, or in parallel on multiple cores. As the thesis shows, existing single-core policies trade-off noticeable improvements in local (remote) for noticeable degradations in remote (local) response times. A new lazy policy for scheduling these tasks on a single-core is introduced that trades-off an unnoticeable degradation in performance of some users for a much larger noticeable improvement in performance of others. The thesis also shows that on multi-core devices, the tasks should always be scheduled on separate cores. The self-optimizing system adjusts the processing architecture, communication architecture, and scheduling policy based on response time predictions given by a new analytical model. Both the analytical model and the self-optimizing system are validated through simulations and experiments in practical scenarios

Annotations of maps in collaborative work at a distance

This thesis inquires how map annotations can be used to sustain remote collaboration. Maps condense the interplay of space and communication, solving linguistic references by linking conversational content to the actual places to which it refers. This is a mechanism people are accustomed to. When we are face-to-face, we can point to things around us. However, at a distance, we need to recreate a context that can help disambiguate what we mean. A map can help recreate this context. However other technological solutions are required to allow deictic gestures over a shared map when collaborators are not co-located. This mechanism is here termed Explicit Referencing. Several systems that allow sharing maps annotations are reviewed critically. A taxonomy is then proposed to compare their features. Two filed experiments were conducted to investigate the production of collaborative annotations of maps with mobile devices, looking for the reasons why people might want to produce these notes and how they might do so. Both studies led to very disappointing results. The reasons for this failure are attributed to the lack of a critical mass of users (social network), the lack of useful content, and limited social awareness. More importantly, the study identified a compelling effect of the way messages were organized in the tested application, which caused participants to refrain from engaging in content-driven explorations and synchronous discussions. This last qualitative observation was refined in a controlled experiment where remote participants had to solve a problem collaboratively, using chat tools that differed in the way a user could relate an utterance to a shared map. Results indicated that team performance is improved by the Explicit Referencing mechanisms. However, when this is implemented in a way that is detrimental to the linearity of the conversation, resulting in the visual dispersion or scattering of messages, its use has negative consequences for collaborative work at a distance. Additionally, an analysis of the eye movements of the participants over the map helped to ascertain the interplay of deixis and gaze in collaboration. A primary relation was found between the pair's recurrence of eye movements and their task performance. Finally, this thesis presents an algorithm that detects misunderstandings in collaborative work at a distance. It analyses the movements of collaborators' eyes over the shared map, their utterances containing references to this workspace, and the availability of "remote" deictic gestures. The algorithm associates the distance between the gazes of the emitter and gazes of the receiver of a message with the probability that the recipient did not understand the message

Evaluating groupware usability at the cognitive level of human action

Tese de doutoramento, Informática (Engenharia Informática), Universidade de Lisboa, Faculdade de Ciências, 2010This dissertation explores the importance of the cognitive level of human action in the evaluation and improvement of groupware usability. This research is motivated by the problem that current methods focus on the rational and social levels of human action and yet an increasing number of users relies on computers to fulfil collaborative tasks dominated by perceptual, cognitive, and motor skill. The first contribution of this research is a groupware interface model that leverages existing knowledge on cognitive-level behaviour with single-user interfaces by expanding its application to multi-user interfaces. To do this, I show that the key differences between users interacting with the computer and interacting with other users through the computer can be supported by specialised groupware information flows and input/output devices. The second contribution of this dissertation is a pair of methods for predicting groupware usability at the cognitive level of human action. The first method applies to scenarios of collaboration occurring routinely in shared workspaces. The second aims at capturing the intertwined nature of mixed-focus collaboration, encompassing shared and private workspaces. I use the methods to evaluate and compare the usability of competing designs in four scenarios of collaboration. The methods do not require user testing or functioning prototypes, so they can be integrated into the iterative process of interactive systems design. The third contribution of this research is the evaluation of an attentive electronic brainstorming tool, which implements a novel attentive device that adjusts the delivery of group awareness information according to users’ natural task switching between doing individual work and attending to the group. I present results from a laboratory experiment, which indicate that groups produced 9.6% more ideas when compared to the immediate broadcast of ideas and provide evidence suggesting that the usability improvement was due to the mitigation of information overload.Esta dissertação explora a importância do nível cognitivo da actividade humana, no qual as tarefas demoram segundos a realizar e são tipicamente repetitivas, na avaliação e melhoria da usabilidade de sistemas de trabalho cooperativo suportado por computador, também designados por groupware. Estes sistemas de computadores permitem que grupos de interesse, como amigos e colegas, possam partilhar e organizar actividades de forma flexível e económica, onde o tempo e a distância deixam de ser obstáculos à colaboração. Alguns exemplos de groupware incluem os mensageiros instantâneos, usados por centenas de milhões de pessoas no mundo inteiro, os jogos multi-utilizador, que já atingiram cerca de dezasseis milhões de jogadores, bem como uma gama cada vez mais alargada de aplicações de escritório que estão a ser disponibilizadas na Internet. Com base nesta evidência, uma assumpção desta dissertação é que os sistemas de groupware estão a ficar cada vez mais ubíquos. O problema abordado nesta investigação é que os métodos actuais de avaliação da usabilidade de groupware omitem o nível cognitivo da actividade humana, e, no entanto, as nossas características psicológicas, como a percepção, cognição, e capacidade motora, dominam a execução de tarefas de colaboração rápidas, mas normalmente muito repetitivas. Uma consequência desta situação é que faltam instrumentos aos designers e investigadores de groupware que lhes permitam fazer optimizações de usabilidade de granularidade fina. Isto acontece porque os métodos actuais de avaliação da usabilidade visam tarefas colaborativas de relativa longa duração (que demoram minutos, horas, ou mais, a completar) e, portanto, baseiam-se em abstracções para conter o grau de complexidade da avaliação. Desta forma, as optimizações tendem a abranger vários passos de colaboração de granularidade fina de uma só vez, o que causa problemas porque a usabilidade de sistemas de groupware, como na maioria dos sistemas computacionais, está inerentemente ligada aos detalhes da interface com o utilizador. Estas optimizações, mesmo que de pequena expressão individual, podem acarretar um efeito multiplicador significativo dado o crescente número de utilizadores de groupware, especialmente na Internet. Outra consequência do nível cognitivo da acção humana ser negligenciado das avaliações de usabilidade de groupware é que o design da interface com o utilizador pode estar indevidamente alinhado com as características psicológicas humanas, o que pode fazer com que as tarefas colaborativas exijam uma carga de trabalho que excede as nossas capacidades limitadas de processamento de informação. Aliás, os utilizadores que realizam trabalho em grupo estão particularmente expostos a uma sobrecarga de informação porque têm de acompanhar o que se passa no grupo para além de realizarem trabalho individual, isto é, têm de dividir a atenção entre múltiplos fluxos de informação. Esta carga de trabalho pode penalizar a usabilidade dos sistemas de groupware devido ao aumento da probabilidade dos utilizadores não serem capazes de colaborar adequadamente. Dada esta situação, a minha questão de investigação é: como fazer avaliações ao nível cognitivo da actividade humana para melhorar a usabilidade de tarefas colaborativas realizadas através de sistemas de groupware? As avaliações de usabilidade ao nível cognitivo são bastante conhecidas no contexto das aplicações mono-utilizador, ao ponto de um conjunto de conhecimentos da psicologia aplicada ter sido reunido em modelos de engenharia de desempenho humano que predizem tempos de execução numa gama variada de tarefas de interacção pessoa-máquina. Estes modelos foram já, inclusivamente, aplicados no contexto de trabalho de grupo, mas sempre com a limitação de os utilizadores estarem restringidos a papéis individualistas e de a colaboração ficar de fora dos limites do sistema ou então ser abstraída. Em contraste, nesta dissertação estou interessado em avaliar as tarefas de colaboração realizadas através do sistema de groupware. A primeira contribuição desta investigação é um modelo da interface do groupware, o qual alavanca o conhecimento existente sobre o comportamento humano com interfaces mono-utilizador, baseado em modelos de engenharia que predizem o desempenho humano, através da expansão da sua aplicação a interfaces multi-utilizador. Para fazer isto mostro que as diferenças fundamentais entre os utilizadores interagirem com o computador (para trabalharem individualmente) e interagirem com outros utilizadores através do computador (para colaborar) podem ser suportadas por fluxos de informação e dispositivos de input/output especializados. Este modelo tem como propósito ajudar o designer a organizar o espaço de soluções numa gama alargada de sistemas de groupware. A segunda contribuição desta dissertação é um par de métodos para avaliar a usabilidade de sistemas de groupware ao nível cognitivo da actividade humana. O primeiro método é aplicável a cenários críticos de colaboração que ocorram rotineiramente em espaços de trabalho partilhados e define usabilidade em termos do tempo necessário para executar tarefas colaborativas, tal como estimado pelos modelos de engenharia de desempenho humano. Na dissertação aplico este método para avaliar e comparar a usabilidade de alternativas de design em três casos de colaboração em espaços partilhados. O segundo método visa capturar a natureza complexa e entrecruzada da colaboração que abrange tanto espaços partilhados como privados, bem como capturar os objectivos frequentemente conflituosos dos utilizadores enquanto estão a trabalhar individualmente ou quando estão a interagir com o grupo. Para fazer isto, combino estimativas de tempos de execução de tarefas com contribuições dessas tarefas para a progressão do grupo em direcção a um objectivo comum, em termos de produtividade individual, oportunidades criadas para os outros, e restrições para o trabalho de outros utilizadores. Na dissertação aplico este método a um jogo colaborativo, e mostro que, se para alguma outra coisa mais, este método serve para forçar o designer de groupware a pensar sobre as contrapartidas entre uma interface que permite aos utilizadores enquanto indivíduos serem mais produtivos e outra que permite um melhor desempenho do grupo enquanto um todo. Os dois métodos de avaliação não requerem testes com utilizadores ou a construção de protótipos de groupware para produzirem resultados de usabilidade, o que atesta a sua natureza formativa, e permite a sua integração no processo iterativo de design de sistemas interactivos. A terceira contribuição desta investigação é a avaliação da usabilidade de um sistema de groupware atentivo, que implementa um novo dispositivo de gestão da atenção humana, chamado opportunity seeker , o qual tem como propósito mitigar a sobrecarga de informação em cenários de colaboração síncrona, isto é, em que todos os elementos do grupo estão a trabalhar em simultâneo. O opportunity seeker intercepta e guarda numa memória tampão a informação de estado sobre o grupo e ajusta automaticamente a entrega dessa informação a cada utilizador em função da alternância natural entre este estar a realizar trabalho individual e estar a prestar atenção ao grupo. Na dissertação mostro como este dispositivo pode ser adaptado e instalado numa ferramenta electrónica para geração de ideias, chamada ABTool, e como a fronteira entre os dois estados de atenção pode ser detectada através de actividade no teclado. Para avaliar os efeitos do opportunity seeker na usabilidade da ferramenta ABTool, realizei uma experiência de laboratório em que pedi a grupos de voluntários para submeterem ideias em paralelo o mais rapidamente possível, e recolhi evidência de que quando os grupos estiveram sob a influência do opportunity seeker o número de ideias geradas aumentou em 9.6% em comparação com a condição em que todas as ideias eram imediatamente difundidas por todos os utilizadores. Adicionalmente, levei a cabo uma análise post-hoc que mostra que o opportunity seeker reduziu o número de entregas de ideias em 44.1%, pois combinou as ideias em pequenos lotes, e que isso se traduziu em 54.7% mais tempo para os utilizadores escreverem ideias sem serem interrompidos pela recepção de ideias de outros utilizadores. Nestas condições, os utilizadores foram 18.8% mais rápidos a alternar entre a escrita de uma ideia, o que fizeram em 16.3% menos tempo, e ler novas ideias de outros utilizadores. Estes resultados evidenciam que o opportunity seeker criou condições para mitigar a sobrecarga de informação e mostram que a usabilidade de sistemas de groupware pode ser melhorada através de avaliações focadas nas limitações da capacidade de processamento de informação humana. Com este conjunto de contribuições, mostrei que o nível cognitivo da actividade humana tem um papel determinante na avaliação da usabilidade de sistemas de groupware, complementando os níveis racional e social que têm sido tradicionalmente considerados por outros métodos de avaliação.Portuguese Foundation for Science and Technology(Fundação para a Ciência e Tecnologia), through project PTDC/EIA/67589/2006 and the Multiannual Funding Programme

Gender differences in navigation dialogues with computer systems

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.Gender is among the most influential of the factors underlying differences in spatial abilities, human communication and interactions with and through computers. Past research has offered important insights into gender differences in navigation and language use. Yet, given the multidimensionality of these domains, many issues remain contentious while others unexplored. Moreover, having been derived from non-interactive, and often artificial, studies, the generalisability of this research to interactive contexts of use, particularly in the practical domain of Human-Computer Interaction (HCI), may be problematic. At the same time, little is known about how gender strategies, behaviours and preferences interact with the features of technology in various domains of HCI, including collaborative systems and systems with natural language interfaces. Targeting these knowledge gaps, the thesis aims to address the central question of how gender differences emerge and operate in spatial navigation dialogues with computer systems. To this end, an empirical study is undertaken, in which, mixed-gender and same-gender pairs communicate to complete an urban navigation task, with one of the participants being under the impression that he/she interacts with a robot. Performance and dialogue data were collected using a custom system that supported synchronous navigation and communication between the user and the robot. Based on this empirical data, the thesis describes the key role of the interaction of gender in navigation performance and communication processes, which outweighed the effect of individual gender, moderating gender differences and reversing predicted patterns of performance and language use. This thesis has produced several contributions; theoretical, methodological and practical. From a theoretical perspective, it offers novel findings in gender differences in navigation and communication. The methodological contribution concerns the successful application of dialogue as a naturalistic, and yet experimentally sound, research paradigm to study gender and spatial language. The practical contributions include concrete design guidelines for natural language systems and implications for the development of gender-neutral interfaces in specific domains of HCI

Proceedings of the 6th international conference on disability, virtual reality and associated technologies (ICDVRAT 2006)

The proceedings of the conferenc