Stereographic virtual environments display data in such a way that a user perceives objects within the displayed environment to be separated in depth from the display itself. The effectiveness of stereographic virtual environments as learning tools has been evaluated relative to factors such as multidimensional cues, user interaction, and learner characteristics. This study has examined the relationship between two evaluative factors: the presence of stereographic depth cues and field dependence, a learner characteristic associated with performance on visual tasks. Adult learners were identified on a field dependence continuum based on scores on the Group Embedded Figures Test. Each student received instruction related to the heart using stereographic materials or nonstereographic materials, depending on assignment to treatment group. All participants were given two tests, identification and terminology, following this instruction. The scores on the combination of these tests, denoted as the Modified Total Criterion Test (MTCT), represented the level of visual recall relative to the instructional materials reviewed. Analyses of variance revealed an interaction effect between the level of field dependence and the presence of stereographic depth cues within a virtual environment such that field independent participants scored higher on tests of visual recall within stereographic conditions versus nonstereographic conditions and field dependent participants scored lower within stereographic conditions versus nonstereographic conditions. / Ph. D.

A Distributed Virtual Environment (DVE) system provides a shared virtual environment where physically separated users can interact and collaborate over a computer network. More simultaneous DVE users could result in intolerable system performance degradation. We address the three major challenges to improve DVE scalability: effective DVE system performance measurement, understanding the controlling factors of system performance/quality and determining the consequences of DVE system changes. We propose a DVE Scalability Engineering (DSE) process that addresses these three major challenges for DVE design. DSE allow us to identify, evaluate, and leverage trade-offs among DVE resources, the DVE software, and the virtual environment. DSE has three stages. First, we show how to simulate different numbers and types of users on DVE resources. Collected user study data is used to identify representative user types. Second, we describe a modeling method to discover the major trade-offs between quality of service and DVE resource usage. The method makes use of a new instrumentation tool called ppt. ppt collects atomic blocks of developer-selected instrumentation at high rates and saves it for offline analysis. Finally, we integrate our load simulation and modeling method into a single process to explore the effects of changes in DVE resources. We use the simple Asteroids DVE as a minimal case study to describe the DSE process. The larger and commercial Torque and Quake III DVE systems provide realistic case studies and demonstrate DSE usage. The Torque case study shows the impact of many users on a DVE system. We apply the DSE process to significantly enhance the Quality of Experience given the available DVE resources. The Quake III case study shows how to identify the DVE network needs and evaluate network characteristics when using a mobile phone platform. We analyze the trade-offs between power consumption and quality of service. The case studies demonstrate the applicability of DSE for discovering and leveraging tradeoffs between Quality of Experience and DVE resource usage. Each of the three stages can be used individually to improve DVE performance. The DSE process enables fast and effective DVE performance improvement. / Ph. D.

Few researchers have addressed the important issue of three-dimensional multiple object selection (MOS) in immersive Virtual Environments (VEs). We have developed a taxonomy of the MOS task as a framework for exploring the design space of these techniques. In this thesis, we describe four techniques for selecting multiple objects in immersive VEs. Of the four techniques, two are serial (where only one object can be indicated per operation), and two are parallel (where one or more objects may be indicated per operation). Within each of the two categories we also investigated two metaphors of interaction: a 3D spatial metaphor and the pen and tablet metaphor. Two usability studies were used to evaluate the four techniques, iterate their designs, and gain a deeper understanding of the design space of MOS techniques. The results from our studies show that parallel MOS techniques can select objects faster than serial techniques as the number of target objects increase. We also show that effective techniques for MOS in immersive VEs can be created using both pen and tablet and 3D metaphors. / Master of Science

Multiplatform virtual environment (VE) development is fast-becoming a realization for today’s developers. 3D user interfaces (3DUIs) can easily be ported to a variety of VE systems. However, few researchers have addressed the need to intelligently migrate 3DUIs across VE systems. We claim that the naïve migration of 3D interaction techniques (3DITs) to other VE systems could result in decreases in usability. We also claim that device specificity can be used to increase usability on these other VE systems. In this thesis, we have chosen three manipulation 3DITs to naively migrate across a set of four VE systems. We use an exploratory usability study to identify any usability issues stemming from our naïve migrations. After finding decreases in usability in select migrations, we redesigned two of the 3DITs for device specificity. We investigated the benefits of our redesigns with usability studies on the original, naïve, and redesigned implementations of both 3DITs. Results from our studies are mixed. In one case we demonstrate that device specificity can be used effectively to increase 3DIT migratability. As a result from our experience in this work, we have learned several lessons in device-specific design as well as 3DIT migration. / Master of Science

Museums are rich and complex learning experiences, using a variety of interactive approaches to engage their audiences. However, the largely unstructured nature of free-choice learning calls for alternative approaches that can effectively engage groups of school age students with diverse cultural backgrounds. In these informal learning spaces employing digital content, classroom-size student groups do not get adequate exposure to content and if they do, it is either through individual interactions with digital exhibits or in a passive style instruction offered by a museum docent to the whole group. This research aims to identify which elements of collocated group collaboration, virtual environments, and serious games can be leveraged for an enhanced learning experience for small and large groups of middle school students. We created a conceptual framework based on the Contextual Model of Learning in museums (John H. Falk and Dierking, 2000) and the most effective educational elements of Virtual Environments (VEs) and Serious Games, in order to increase engagement and social presence and facilitate learning. We then developed C-OLiVE (Collaborative Orchestrated Learning in Virtual Environments), an interactive virtual learning environment supporting group collaboration, which we used as a testbed to respond to our research questions. Our overall hypothesis is that synchronous, collocated, group collaboration will afford greater learning and an improved game experience compared to the conventional approaches used in these spaces so far. We ran three experiments and a case study with 790 students in private and public middle schools, summer camps, and museums both in the US and in Greece. Findings partly supported our hypothesis, mainly during our small group interaction experiments, in which simultaneous interaction of students was found to be associated with increased learning. Guidance of a passive experience was effective in facilitating the more cognitively challenged group of students in a Greek museum. Our audience interaction studies revealed increased retention of information two days after the game. Agency was found to significantly predict learning in all our studies. Engagement and social presence were mostly correlated with higher levels of involvement and agency in the game. / Ph. D. / Museums are rich and complex learning experiences, using a variety of interactive approaches to engage their audiences. However, the largely unstructured nature of free-choice learning calls for alternative approaches that can effectively engage groups of school age students with diverse cultural backgrounds. In these informal learning spaces employing digital content, classroom-size student groups do not get adequate exposure to content and if they do, it is either through individual interactions with digital exhibits or in a passive style instruction offered by a museum docent to the whole group. This research aims to identify which elements of collocated group collaboration, virtual environments, and serious games can be leveraged for an enhanced learning experience for small and large groups of middle school students. We created a conceptual framework based on a theoretical model from museum studies, called the <i>Contextual Model of Learning</i>, and the most effective educational elements of Virtual Environments (VEs) and Serious Games, or learning games, in order to increase <i>engagement</i> and <i>social presence</i> (i.e., the feeling of interconnectedness between participants) and facilitate learning. We then developed an interactive virtual learning environment supporting group collaboration, which we used as a testbed to respond to our research questions. Our overall hypothesis is that synchronous, collocated, group collaboration will afford greater learning and an improved game experience compared to the conventional approaches used in these spaces so far. We ran three experiments and a case study with 790 students in private and public middle schools, summer camps, and museums both in the US and in Greece. Findings partly supported our hypothesis, mainly during our small group interaction experiments, in which simultaneous interaction of students was found to be associated with increased learning. Guidance of a passive experience was effective in facilitating the more cognitively challenged group of students in a Greek museum. Our audience interaction studies revealed increased retention of information two days after the game. Agency (or level of control) in the game significantly predicted learning in all our studies. Engagement and social presence were correlated with higher levels of involvement and agency.

Effective coastal planning is inclusive and incorporates the variety of user needs, values, and interests associated with coastal environments. This requires understanding how people relate to coastal environments as ‘places’, imbued with values and meanings, and accordingly, tools that can capture place and connect with people’s ‘sense of place’ have the potential for supporting effective coastal management strategies. Realistic, immersive geographical visualizations, i.e., geovisualizations, theoretically hold potential to serve such a role in coastal planning. However, significant research gaps exist around this application context. Firstly, place theory and geovisualizations are rarely explicitly linked in the same studies, leaving questions around the (potential) relationship between these tools and sense of place. Secondly, geovisualization work has focused on terrestrial environments, and research on how to realistically model coastal places is currently in its infancy. This dissertation aims to address these gaps by pursuing two research objectives. The first objective is to explore the ‘human component’ of geovisualizations, referring to how these tools operate within the social and cultural dimensions germane to environmental management plans and processes. In accordance with the discussion above, this exploration is framed through place theories and concepts, and regards realistic geovisualizations as ‘place-based’ tools. The second objective concerns the coastal context, and it involves elucidating the considerations around developing and using terrestrial-to-marine geovisualizations as tools for inclusive coastal planning and management. The dissertation is composed of five manuscripts, which have been prepared as standalone articles for submission to academic journals. Each manuscript details a study designed to support an aspect of the research objectives, respectively serving (1) to develop a theory of geovisualizations as place-based tools, (2) to explore the theory in the coastal context, (3) to examine the relationship between sense of place and one’s mental visualization of place, (4) to develop a coastal geovisualization under place-based considerations and examine its capacity for connecting to sense of place, and (5) to assess the geovisualization’s potential as a tool for inclusive coastal planning efforts. The first and second study consist of literature review work. The third study involves a survey administered to residents of the Capital Regional District, which collected data for examining a potential relationship between the way people visualize coastal places and how they value and relate to these places. The fourth and fifth study involve developing a coastal geovisualization of Sidney Spit, and then employing focus groups to examine its ability for connecting with people’s sense of place (i.e., fourth study) and utility as a tool for inclusive planning (i.e., fifth study). Outcomes from the first study include a theory on how geovisualizations can function as place-based tools, and this was developed by integrating place concepts with ideas and conceptual models from human-media interaction and sense of presence research. The second study produced insight on how values and interests of different coastal user groups can influence understandings and perceptions of coastal places, and it used this insight to develop recommendations for coastal geovisualizations - full navigability, dynamic elements, and flexibility (i.e., allowing for continual modification and scenario building). The third study produced empirical evidence that place-based values and interests (i.e., framed through sense of place and concerns for place) can influence one’s mental visualization of place in terms of the types of elements people include and perspectives they take in said visualization. The fourth study demonstrated that the presence of certain elements in coastal geovisualizations (such as people, dogs, birds, marine life, vegetation, and boats) can contribute to realism and sense of place; however, simultaneously, deficiencies in numbers and varieties of these elements can detract from realism and sense of place. In addition, the fourth study found that the incorporation of soundscape and viewshed elements is significant for the tool’s ability to connect with sense of place. The fifth study demonstrated the geovisualization’s usefulness for assessing certain qualities of management scenarios, such as aesthetics and functionality of fencing around a restoration area and potential viewshed impacts associated with locations of moored boats. The study also found that incorporating navigability into the geovisualization proved to be valuable for enhancing understandings around scenarios that hold implications for the marine environment because it allowed users to cross the land-sea interface and experience underwater places. / Graduate

This thesis focuses on virtual restorative environments – specifically, the way that natural environments have been created in a virtual context to elicit beneficial effects on restoration and stress recovery. As the field of restorative environment research is mostly concerned with studying the environment itself, the interaction between participant and environment tends to consist of open exploration, and other ways to interact are often overlooked. The aim of this thesis was therefore to construct a virtual restorative environment with an additional possibility to interact, and to explore how the interaction is connected to a virtual environment’s perceived restorativeness. To gain deeper understanding about how different people perceived the virtual environments, the experiment was conducted using qualitative measures such as questionnaires, open questions and interviews. The results indicate that the perception of a virtual environment’s restorativeness is a very subjective matter, as the individual differences between the participants affected the way that they perceived the environments.

This thesis describes a study carried out with the aim of discovering user preferences as to the design of 3-dimensional virtual worlds for accessing information. No literature was found which dealt with this topic, and it was therefore thought that, rather than ask users to make a selection from arbitrarily-chosen designs, it would be informative to consult the users from the beginning of the design process. To this end, a Grounded Theory methodology was adopted, and users were selected from postgraduate students and staff from Information Management courses at the Robert Gordon University, Aberdeen. Three “rounds” of interviews were conducted. The first round was concerned with finding out what ideas for a world design people would have, the second with testing four worlds derived from the first round, and the third with exploring further ideas that users had, based on their experience of the test worlds. At each stage of the process, emergent theories were constructed, and modified according to subsequent findings. It was established that the factors which influenced this group of users in their preferences for the design of worlds were not structural, as might have been assumed, but instead were related to properties such as familiarity, organisation, assistance, and quality of information and presentation. When the results were examined in the context of developments in the use of virtual environments, it was found that they provide a theoretical underpinning for practices such as the provision of “conventional” library structures in the popular online environment Second Life. This is not a statistical exercise, but it would appear that there are no significant differences based on the criteria of age, gender, or whether a user was staff or student. More thorough studies would be required to determine this absolutely, but for the moment it appears more useful to draw a broad set of conclusions. ii Issues were identified which indicate potentially rewarding areas for further research and design. Specifically, it would be of interest to discover whether the affective responses of these groups are also common to other groups, and to experiment further with worlds designed in the light of the current findings. Further investigation of the small number of cases in which users do not respond to the worlds would also be desirable, to determine whether this response is characteristic of a group of people who will not react positively to any world, or whether these users simply reacted negatively to the examples presented.

The growing popularity of online virtual communities such as Second Life and ActiveWorlds demands the presence of intelligent agents to assist users in their daily online activities (e.g., exploring, shopping, and socializing). As these virtual environments become more crowded, multiple agents are needed to support the increasing number of users. Multi-agent environments, however, can suffer from the problem of resource competition among agents. It is therefore necessary that agents within multi-agent environments include a coordination mechanism to prevent unrealistic behaviors. Moreover, it is essential that these agents exhibit some form of intelligence, or the ability to learn, to support realism as well as to eliminate the need for developers to write separate scripts for each task the agents are required to perform. This research presents a coordinated reinforcement learning framework which can be used to develop task-oriented intelligent agents in multi-agent virtual environments. The framework contains a combination of a "next available agent" coordination model and a reinforcement learning model consisting of existing temporal difference reinforcement learning algorithms. Furthermore, the framework supports evaluations of reinforcement learning algorithms to determine which methods are best suited for task-oriented intelligent agents in dynamic, multi-agent virtual environments. To assess the effectiveness of the temporal difference reinforcement algorithms used in this study (Q-learning and Sarsa), experiments were conducted that measured an agent's ability to learn three tasks commonly performed by workers in a café environment. These tasks were basic sandwich making (BSM), complex sandwich making (CSM), and dynamic sandwich making (DSM). The BSM task consisted of four steps. The CSM and DSM tasks contained an additional fifth step. The agent learned the BSM and CSM tasks from scratch while the DSM task was learned after the agent became skillful in BSM. The measurements used to evaluate the efficiency of the Q-learning and Sarsa algorithms were the percentage of successful and optimally successful episodes performed by the agent and the average number of time steps taken by the agent to complete a successful episode. The experiments were run using both a fixed (FEP) and variable (VEP) ε-greedy probability rate. Results showed that the Sarsa reinforcement learning algorithm, on average, outperformed the Q-learning algorithm in almost all experiments except when measuring the percentage of successfully completed episodes using FEP for CSM and DSM, in which Sarsa performed almost equally as well as Q-learning. Overall, experiments utilizing VEP resulted in higher percentages of successes and optimal successes, and showed convergence to the optimal policy when measuring the average number of time steps per successful episode.

For both the CAVETM and the adaptable technology possessed by the University of New Orleans, crystal eye glasses are used to produce a stereoscopic view, and an ascension flock of birds tracking system is employed for tracking of the user's head position and position of a wand in 3D space. It is argued that with these immersive technologies along the use of gestures and hand movements should provide a more natural interface with the immersive virtual environment. This allows a more rapid and efficient set of actions to recognize geometry, interaction with a spatial environment, the ability to find errors, or navigate through an environment. The wand interface is used to provide an improved means of interaction. This study quantitatively measures the differences in interaction when compared with traditional human computer interfaces. This work uses competitive usability in four different Benchmarks: 1) navigation, 2) error detection/correction, 3) spatial awareness, and 4) a “shopping list” of error identifications. This work expands on [Butler & Satter's, 2005] work by conducting tests in the CAVETM system, rather than principally employing workbench technology. During testing, the testers are given some time to “play around” with the CAVETM environment for familiarity before undertaking a specific exercise. The testers are then instructed regarding tasks to be completed, and are asked to work quickly without sacrificing accuracy. The research team timed each task, counted errors, and recorded activity on evaluation sheets for each Benchmark test. At the completion of the testing scenarios involving Benchmarks 1, 2, 3, or 4, the subjects were given a survey document and asked to respond by checking boxes to communicate their subjective opinions.