246 research outputs found

    Applying a User-centred Approach to Interactive Visualization Design

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    Analysing users in their context of work and finding out how and why they use different information resources is essential to provide interactive visualisation systems that match their goals and needs. Designers should actively involve the intended users throughout the whole process. This chapter presents a user-centered approach for the design of interactive visualisation systems. We describe three phases of the iterative visualisation design process: the early envisioning phase, the global specification hase, and the detailed specification phase. The whole design cycle is repeated until some criterion of success is reached. We discuss different techniques for the analysis of users, their tasks and domain. Subsequently, the design of prototypes and evaluation methods in visualisation practice are presented. Finally, we discuss the practical challenges in design and evaluation of collaborative visualisation environments. Our own case studies and those of others are used throughout the whole chapter to illustrate various approaches

    Systems, interactions and macrotheory

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    A significant proportion of early HCI research was guided by one very clear vision: that the existing theory base in psychology and cognitive science could be developed to yield engineering tools for use in the interdisciplinary context of HCI design. While interface technologies and heuristic methods for behavioral evaluation have rapidly advanced in both capability and breadth of application, progress toward deeper theory has been modest, and some now believe it to be unnecessary. A case is presented for developing new forms of theory, based around generic “systems of interactors.” An overlapping, layered structure of macro- and microtheories could then serve an explanatory role, and could also bind together contributions from the different disciplines. Novel routes to formalizing and applying such theories provide a host of interesting and tractable problems for future basic research in HCI

    Viability in State-Action Space: Connecting Morphology, Control, and Learning

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    Wie können wir Robotern ermöglichen, modellfrei und direkt auf der Hardware zu lernen? Das maschinelle Lernen nimmt als Standardwerkzeug im Arsenal des Robotikers seinen Platz ein. Es gibt jedoch einige offene Fragen, wie man die Kontrolle ĂŒber physikalische Systeme lernen kann. Diese Arbeit gibt zwei Antworten auf diese motivierende Frage. Das erste ist ein formales Mittel, um die inhĂ€rente Robustheit eines gegebenen Systemdesigns zu quantifizieren, bevor der Controller oder das Lernverfahren entworfen wird. Dies unterstreicht die Notwendigkeit, sowohl das Hardals auch das Software-Design eines Roboters zu berĂŒcksichtigen, da beide Aspekte in der Systemdynamik untrennbar miteinander verbunden sind. Die zweite ist die Formalisierung einer Sicherheitsmass, die modellfrei erlernt werden kann. Intuitiv zeigt diese Mass an, wie leicht ein Roboter FehlschlĂ€ge vermeiden kann. Auf diese Weise können Roboter unbekannte Umgebungen erkunden und gleichzeitig AusfĂ€lle vermeiden. Die wichtigsten BeitrĂ€ge dieser Dissertation basieren sich auf der ViabilitĂ€tstheorie. ViabilitĂ€t bietet eine alternative Sichtweise auf dynamische Systeme: Anstatt sich auf die Konvergenzeigenschaften eines Systems in Richtung Gleichgewichte zu konzentrieren, wird der Fokus auf Menge von FehlerzustĂ€nden und die FĂ€higkeit des Systems, diese zu vermeiden, verlagert. Diese Sichtweise eignet sich besonders gut fĂŒr das Studium der Lernkontrolle an Robotern, da StabilitĂ€t im Sinne einer Konvergenz wĂ€hrend des Lernprozesses selten gewĂ€hrleistet werden kann. Der Begriff der ViabilitĂ€t wird formal auf den Zustand-Aktion-Raum erweitert, mit ViabilitĂ€tsmengen von Staat-Aktionspaaren. Eine ĂŒber diese Mengen definierte Mass ermöglicht eine quantifizierte Bewertung der Robustheit, die fĂŒr die Familie aller fehlervermeidenden Regler gilt, und ebnet den Weg fĂŒr ein sicheres, modellfreies Lernen. Die Arbeit beinhaltet auch zwei kleinere BeitrĂ€ge. Der erste kleine Beitrag ist eine empirische Demonstration der Shaping durch ausschliessliche Modifikation der Systemdynamik. Diese Demonstration verdeutlicht die Bedeutung der Robustheit gegenĂŒber Fehlern fĂŒr die Lernkontrolle: AusfĂ€lle können nicht nur SchĂ€den verursachen, sondern liefern in der Regel auch keine nĂŒtzlichen Gradienteninformationen fĂŒr den Lernprozess. Der zweite kleine Beitrag ist eine Studie ĂŒber die Wahl der Zustandsinitialisierungen. Entgegen der Intuition und der ĂŒblichen Praxis zeigt diese Studie, dass es zuverlĂ€ssiger sein kann, das System gelegentlich aus einem Zustand zu initialisieren, der bekanntermassen unkontrollierbar ist.How can we enable robots to learn control model-free and directly on hardware? Machine learning is taking its place as a standard tool in the roboticist’s arsenal. However, there are several open questions on how to learn control for physical systems. This thesis provides two answers to this motivating question. The first is a formal means to quantify the inherent robustness of a given system design, prior to designing the controller or learning agent. This emphasizes the need to consider both the hardware and software design of a robot, which are inseparably intertwined in the system dynamics. The second is the formalization of a safety-measure, which can be learned model-free. Intuitively, this measure indicates how easily a robot can avoid failure, and enables robots to explore unknown environments while avoiding failures. The main contributions of this dissertation are based on viability theory. Viability theory provides a slightly unconventional view of dynamical systems: instead of focusing on a system’s convergence properties towards equilibria, the focus is shifted towards sets of failure states and the system’s ability to avoid these sets. This view is particularly well suited to studying learning control in robots, since stability in the sense of convergence can rarely be guaranteed during the learning process. The notion of viability is formally extended to state-action space, with viable sets of state-action pairs. A measure defined over these sets allows a quantified evaluation of robustness valid for the family of all failure-avoiding control policies, and also paves the way for enabling safe model-free learning. The thesis also includes two minor contributions. The first minor contribution is an empirical demonstration of shaping by exclusively modifying the system dynamics. This demonstration highlights the importance of robustness to failures for learning control: not only can failures cause damage, but they typically do not provide useful gradient information for the learning process. The second minor contribution is a study on the choice of state initializations. Counter to intuition and common practice, this study shows it can be more reliable to occasionally initialize the system from a state that is known to be uncontrollable

    Designing Effective Interfaces for Older Users

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    The thesis examines the factors that need to be considered in order to undertake successful design of user interfaces for older users. The literature on aging is surveyed for age related changes that are of relevance to interface design. The findings from the literature review are extended and placed in a human context using observational studies of older people and their supporters as these older people attempted to learn about and use computers. These findings are then applied in three case studies of interface design and product development for older users. These case studies are reported and examined in depth. For each case study results are presented on the acceptance of the final product by older people. These results show that, for each case study, the interfaces used led to products that the older people evaluating them rated as unusually suitable to their needs as older users. The relationship between the case studies and the overall research aims is then examined in a discussion of the research methodology. In the case studies there is an evolving approach used in developing the interface designs. This approach includes intensive contribution by older people to the shaping of the interface design. This approach is analyzed and is presented as an approach to designing user interfaces for older people. It was found that a number of non-standard techniques were useful in order to maximize the benefit from the involvement of the older contributors and to ensure their ethical treatment. These techniques and the rationale behind them are described. Finally the interface design approach that emerged has strong links to the approach used by the UTOPIA team based at the university of Dundee. The extent to which the thesis provides support for the UTOPIA approach is discussed

    An Assessment of Contextual Design and Its Applicability to the Design of Educational Technologies

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    Thesis (PhD) - Indiana University, School of Education, 2008Increased use of computing technology in support of learning necessitates the collaboration of instructional designers with technology designers. Yet the instructional designer portrayed in current instructional design textbooks does not participate in technology design but instead designs instructional strategies and materials that are implemented by others. For instructional systems design as a field to move towards the kinds of collaborative work required for the development of effective, innovative educational technologies, there is a need for methods that can integrate the concerns and activities of both instructional and technology designers. This research critically examines a human-computer interaction design method, contextual design (CD), assessing how practitioners employ and characterize it as a method and explores its potential utility in instructional systems design. CD is briefly described and available evaluative studies are summarized. Next, three studies are presented: a case study of CD usage in the design of a digital music library, a case study of CD integrating with another design approach called PRInCiPleS, and a learning-oriented analysis of CD work models. Based on the findings of the literature review and these three studies, a practitioner survey and interview guide were developed. Results from 106 survey respondents and 16 interviews characterized CD as a guiding framework and a collection of useful techniques. However, because of its resource requirements and other limitations, the method is rarely used in full or exclusively. Respondents reported valuing the ability of CD to uncover and communicate user needs but also suggested CD did not provide a means of resolving conflicts between user needs and organizational objectives. Implications of these results are explored for three constituencies: developer-designers of instructional places or interactive materials, educators of instructional designers who will work with software developers, and educational researchers and their graduate students

    Distributed information resources and embodied cognition in software application training : interaction patterns in online environments and digital games

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    Research on software application training has been predominantly based on the premise that the user builds an internal functional model of the system. This view of cognition as purely internal has been challenged by studies showing that experts do not remember the exact commands required to complete a task if they are not in front of the computer. Display-based competence suggests that a flow of information takes place between the display and the user, who only holds the necessary information to understand the visual cues and act accordingly. Distributed cognition, however, does not address the perceptual and motor actions necessary to acquire the information from the world and act on it. Embodied cognition attends to this gap. The Soft Constraints Hypothesis suggests that at the 'embodiment level', users will choose between cognitive, perceptual, and motor operators based on a cost-benefit analysis, the cost of the resources measured in milliseconds. It was hypothesized that resources in different environments with various access costs would influence use patterns, and learning strategies and performance. For the purpose of this study, participants completed a 5-lesson course in Flash animation concepts. 50 participants were then assigned to two practice environments that contained a software simulator built based on visual cues and salient task features displayed by the real software. The two practice spaces manipulated the nature of, and access to, information resources, with one featuring game-like task completion. Every action taken during the study was tracked and time-stamped, producing a log file containing around 20,000 records for subsequent analysis. The results showed that information access cost in online environments for software training has a clear impact on the strategies employed, the learning processes engaged, and learning outcomes. Traditional statistical analysis showed significant differences in declarative knowledge of rules, efficiency, and accuracy between groups. These results were complemented with data mining techniques to analyze user sequences as departures from an optimum path. The idea of a dual-learning process taking place when users are learning interactive behaviors, for example command sequences, was supported. A declarative-to-procedural process takes place in low-cost single-task environments whereas in the specific case of educational games, information access cost and concurrent game tasks can trigger a non-attentional cue-based behavior that results in higher task efficiency and accuracy, but has a negative impact on rule verbalization. A design framework for instructional environments mapping instruction-specific resources and their access cost to specific learning processes and outcomes is presented based on findings

    Master of Science

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    thesisThe Residency Review Committee (RRC) requires that general surgery residents document their Surgical Intensive Care Unit (SICU) experiences. To satisfy these requirements we created a web based intranet log to make it easier for residents to track their patients and determine when these requirements were complete. A premium was put on usability to promote acceptance by surgical residents. A prototype web site was designed with input from an attending general surgeon. Three general surgery residents were selected to participate in the iterative design phase. They went through three iterations using a "think-aloud" method while performing tasks on the prototype web site. Each iteration led to improvements to the web site. In a comparison test, a group of seven medical students performed 14 typical web site tasks using both the prototype and the final versions. They were asked to complete a Questionnaire for User Interaction Satisfaction (QUIS) for each version. The time for completion of these tasks was also recorded. The user interaction satisfaction did not show any improvement (F(1,6)=0.13, p=0.912). Similarly, there was no improvement in times for delete and add tasks ( Delete F(1,5) = 0.949, p=0.375, Add F(1,5)=0.267, p=0.628 ); however, the time to complete edit tasks was faster for the final version of the web site (F (1,5)= 14.3, p=0.013). The primary reason for not detecting other differences between the two web sites is likely that the comparison study did not have sufficient power. This was suggested by the participants whose comments favored the final version over the prototype as well as a trend of consistently higher mean subset scores in the final version. The results indicate that differences may be seen when more complex tasks are completed (editing information) versus the two simpler tasks (adding or deleting a patient record in a web site). Future studies should focus on the impact of navigation strategies on speed and data warehouse approaches to creating the application. This study shows the benefits of using an iterative design approach to create a usable web site and demonstrates the importance of further research in the field of usability
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