Now showing 1 - 5 of 5
  • Publication
    Modelling User Navigation
    This paper proposes the use of neural networks as a tool for studying navigation within virtual worlds. Results indicate that the network learned to predict the next step for a given trajectory. The analysis of hidden layer shows that the network was able to differentiate between two groups of users identified on the basis of their performance for a spatial task. Time series analysis of hidden node activation values and input vectors suggested that certain hidden units become specialised for place and heading, respectively. The benefits of this approach and the possibility of extending the methodology to the study of navigation in Human Computer Interaction applications are discussed.
      166
  • Publication
    A Connectionist Model of Spatial Knowledge Acquisition in a Virtual Environment
    This paper proposes the use of neural networks as a tool for studying navigation within virtual worlds. Results indicate that network learned to predict the next step for a given trajectory, acquiring also basic spatial knowledge in terms of landmarks and configuration of spatial layout. In addition, the network built a spatial representation of the virtual world, e.g. cognitive-like map, which preserves the topology but lacks metric accuracy. The benefits of this approach and the possibility of extending the methodology to the study of navigation in Human Computer Interaction are discussed.
      217
  • Publication
    Presence equation : An investigation into cognitive factors underlying presence
    The relationship between presence and cognitive factors such as absorption, creative imagination, empathy, and willingness to experience presence was investigated. Presence was defined, operationalized, and measured using a questionnaire that we devised. Absorption and creative imagination were measured using questionnaires developed in the area of hypnosis, and empathy was assessed through an interpersonal reactivity index. Results indicated significant correlations between presence and each cognitive factor. They showed that persons who are highly fantasy prone, more empathic, more absorbed, more creative, or more willing to be transported to the virtual world experienced a greater sense of presence, Regression analysis led to a presence equation, which could be used to predict presence based on the investigated cognitive factors. Findings are congruent with user characteristics presented by the presence literature and support the position that individual differences are important for the study of presence.
      551Scopus© Citations 121
  • Publication
    Agent Mediation and Management of Virtual Communities : A Redefinition of the Traditional Community Concept
    This paper explores the evolution of the concept of community in the light of computer mediated immersive virtual environments. The traditional concept of community has become strained it its attempts to capture the evolving virtual community. We believe the concept of the virtual community is of paramount importance and examine the extent to which this is being redefined to cater for it. We examine the management and mediation of such environments and specifically the social process associated with the cohabited users. We advocate the use of multi-agent systems in delivering this functionality.
      291Scopus© Citations 1
  • Publication
    Virtual Reality in Surgery: Between satisfaction and Stress
    The present study is focused on usability issues related to laparoscopy, emphasizing the surgeon’s overall satisfaction with the mediated perception of reality. We were particularly interested in assessing the differences between this mini-invasive surgical technique and classical surgery, trying to underline both its advantages and limits. We also tried to evaluate the level of stress induced by this method, among the surgeons who use it on a regular basis, together with the adopted coping strategies. Laparoscopy, even though grounded in classical surgery, has its own distinctive features, which require flexibility in order to facilitate the transfer of skills. Despite its limited range of applicability, used discriminatively and carefully, together with well-organized training sessions, this technique can bring satisfaction to both surgeon and patient.
      159