Components of human experience in virtual environments

Framework is presented for measuring human experience in virtual environment (VE). Human experience is defined as the content of direct observation or participation in an event. Both psychological and emotional properties are integrated into this ongoing person–environment interaction to give an experience meaning and value and to enhance its quality and intensity. The sense of presence, i.e., being in the VE is in the center of psychological study of a human experience in VEs. The ‘Big three’ structure of physical presence consists of perceptual, attentional and cognitive components. However, it is considered to ignore, e.g., emotional and ecological aspects in developing a holistic human experience. In this study, components of physical presence are integrated with three different measures of interaction and a set of motivational and cognitive-affective components. These components are integral in the theory of optimal experience, i.e., flow, which has been studied in various human activities. The results show, how these different experiential components relate each other in VE. It is also shown how common patterns can be found from various experiences and profiled to better understand human–computer interaction.     

A fuzzy trust evaluation method for knowledge sharing in virtual enterprises

The success of virtual enterprises (VEs) depends on the effective sharing of related resources between various enterprises or workers who perform related activities. Specifically, VE success hinges on the integration and sharing of information and knowledge. Trust is an important facilitator of knowledge sharing. However, the trustworthiness of a peer is a vague concept that is dynamic and that often shifts over time or with environmental changes. This study designs a trust-based knowledge-sharing model based on characteristics of VEs and the knowledge structure model to express knowledge associated with VE activities. Subsequently, the factors that affect the trust evaluation are identified based on the characteristics of trust and VEs. Finally, this study develops a knowledge sharing, decision-making framework in which a fuzzy trust evaluation method for sharing knowledge is proposed based on VE activities and the interactions among workers in allied enterprises. The method consists of three sub-methods, including an activity correlation evaluation method, a current trust evaluation method, and an integral trust evaluation method. Under the premises of secure VE knowledge and reasonable access authorization, the proposed knowledge-sharing method provides the trust level between a knowledge-requesting enterprise and a knowledge-supplying enterprise to improve the willingness of the latter to share more valuable knowledge, ultimately increasing the efficiency and competitiveness of VEs.     

A fuzzy trust evaluation method for knowledge sharing in virtual enterprises

The success of virtual enterprises (VEs) depends on the effective sharing of related resources between various enterprises or workers who perform related activities. Specifically, VE success hinges on the integration and sharing of information and knowledge. Trust is an important facilitator of knowledge sharing. However, the trustworthiness of a peer is a vague concept that is dynamic and that often shifts over time or with environmental changes. This study designs a trust-based knowledge-sharing model based on characteristics of VEs and the knowledge structure model to express knowledge associated with VE activities. Subsequently, the factors that affect the trust evaluation are identified based on the characteristics of trust and VEs. Finally, this study develops a knowledge sharing, decision-making framework in which a fuzzy trust evaluation method for sharing knowledge is proposed based on VE activities and the interactions among workers in allied enterprises. The method consists of three sub-methods, including an activity correlation evaluation method, a current trust evaluation method, and an integral trust evaluation method. Under the premises of secure VE knowledge and reasonable access authorization, the proposed knowledge-sharing method provides the trust level between a knowledge-requesting enterprise and a knowledge-supplying enterprise to improve the willingness of the latter to share more valuable knowledge, ultimately increasing the efficiency and competitiveness of VEs.     

Mobility impaired users respond differently than healthy users in virtual environments

Virtual environments (VEs) have been shown to be beneficial in physical rehabilitation, increasing motivation and the range of exercises that can be safely performed. However, little is known about how disabilities may impact a user's responses to a VE, which could affect rehabilitation motivation. Thus, the primary objective of this research is to understand how VEs affect users with mobility impairments (MI). Specifically, we investigate the influence of full body avatars that have canes. To begin investigating this, we designed a VE that included a range of multimodal feedback to induce a strong sense of presence and was novel to the participants. Using this VE, we conducted a study with two different populations: eight persons with MI and eight healthy persons as a control. The healthy participants were of similar demographics (e.g., age, weight, height, and previous VE experience) to the participants with MI who walked with a cane (i.e., on the basis of strict selection criteria to maintain homogeneity). This is one of the first studies to investigate how a VE can affect the gait of the users with MI, physiological response, presence, behavior, and the influence of avatars. Results of the study suggest generalizable guidelines for the design of VEs for users with MI. Copyright © 2014 John Wiley & Sons, Ltd.     

Designing presence for real locomotion in immersive virtual environments: an affordance-based experiential approach

This paper describes a framework for designing systems for real locomotion in virtual environments (VEs) in order to achieve an intense sense of presence. The main outcome of the present research is a list of design features that the virtual reality technology should have in order to achieve such a goal. To identify these features, an approach based on the combination of two design strategies was followed. The first was based on the theory of affordances and was utilized to design a generic VE in which the affordances of the corresponding real environment could be evoked. The second was the experiential design applied to VEs and was utilized to create an experience of locomotion corresponding to that achievable in a real environment. These design strategies were chosen because of their potential to enhance the sense of presence. The proposed list of features can be utilized as an instrument that allows VE designers to evaluate the maturity of their systems and to pinpoint directions for future developments. A survey analysis was performed using the proposed framework, which involved three case studies to determine how many features of the proposed framework were present and their status. The result of such analysis represented a measure of the completeness of the systems design, of the affordances provided to the user, and a prediction of the sense of presence.     

Interaction with an immersive virtual environment corrects users' distance estimates

OBJECTIVE: Two experiments examined whether prior interaction within an immersive virtual environment (VE) enabled people to improve the accuracy of their distance judgments and whether an improved ability to estimate distance generalized to other means of estimating distances. BACKGROUND: Prior literature has consistently found that users of immersive VEs underestimate distances by approximately 50%. METHOD: In each of the two experiments, 16 participants viewed objects in an immersive VE and estimated their distance to them by means of blindfolded walking tasks before and after interacting with the VE. RESULTS: The interaction task significantly corrected users' underestimation bias to nearly veridical. Differences between pre- and post-interaction mean distance estimation accuracy were large (d = 4.63), and significant (p < .001), and they generalized across response task. CONCLUSION: This finding limits the generality of the underestimation effect in VEs and suggests that distance underestimation in VEs may not be a road block to the development of VE applications. APPLICATION: Potential or actual applications of this research include the improvement of VE systems requiring accurate spatial awareness.     

The use of virtual environments based on a modification of the computer game Quake III Arena in psychological experimenting

We investigated whether newly developed virtual 3D environments (VEs) based on a modification of the computer game Quake III Arena^® are suitable for psychological experimenting. Internal validity of data collected in VEs may be threatened due to a priori individual differences in general performance in VE navigation and in susceptibility to cybersickness. The main question was whether individual differences in performance can be diminished by means of training. Additionally, the susceptibility of different subsamples to cybersickness when moving within VEs was examined. 85 participants took part in an experiment where they had to fulfill simple tasks in three VEs. Navigation performance was measured as the time participants needed to make their way through the VEs. Differences in navigation performance between different levels of experience were diminished by training, indicating that internal validity can be obtained. A classification tree reveals that game-inexperienced female participants aged over 31 years have the highest risk of experiencing cybersickness. VEs based on modifications of computer games seem to be an extremely promising and inexpensive possibility for the administration of psychological experiments.     

Training in virtual environments: transfer to real world tasks and equivalence to real task training

Virtual environments (VEs) are extensively used in training but there have been few rigorous scientific investigations of whether and how skills learned in a VE are transferred to the real world. This research aimed to measure and evaluate what is transferring from training a simple sensorimotor task in a VE to real world performance. In experiment 1, real world performances after virtual training, real training and no training were compared. Virtual and real training resulted in equivalent levels of post-training performance, both of which significantly exceeded task performance without training. Experiments 2 and 3 investigated whether virtual and real trained real world performances differed in their susceptibility to cognitive and motor interfering tasks (experiment 2) and in terms of spare attentional capacity to respond to stimuli and instructions which were not directly related to the task (experiment 3). The only significant difference found was that real task performance after training in a VE was less affected by concurrently performed interference tasks than was real task performance after training on the real task. This finding is discussed in terms of the cognitive load characteristics of virtual training. Virtual training therefore resulted in equivalent or even better real world performance than real training in this simple sensorimotor task, but this finding may not apply to other training tasks. Future research should be directed towards establishing a comprehensive knowledge of what is being transferred to real world performance in other tasks currently being trained in VEs and investigating the equivalence of virtual and real trained performances in these situations.     

Training in virtual environments: transfer to real world tasks and equivalence to real task training

Virtual environments (VEs) are extensively used in training but there have been few rigorous scientific investigations of whether and how skills learned in a VE are transferred to the real world. This research aimed to measure and evaluate what is transferring from training a simple sensorimotor task in a VE to real world performance. In experiment 1, real world performances after virtual training, real training and no training were compared. Virtual and real training resulted in equivalent levels of post-training performance, both of which significantly exceeded task performance without training. Experiments 2 and 3 investigated whether virtual and real trained real world performances differed in their susceptibility to cognitive and motor interfering tasks (experiment 2) and in terms of spare attentional capacity to respond to stimuli and instructions which were not directly related to the task (experiment 3). The only significant difference found was that real task performance after training in a VE was less affected by concurrently performed interference tasks than was real task performance after training on the real task. This finding is discussed in terms of the cognitive load characteristics of virtual training. Virtual training therefore resulted in equivalent or even better real world performance than real training in this simple sensorimotor task, but this finding may not apply to other training tasks. Future research should be directed towards establishing a comprehensive knowledge of what is being transferred to real world performance in other tasks currently being trained in VEs and investigating the equivalence of virtual and real trained performances in these situations.     

VU-flow: a visualization tool for analyzing navigation in virtual environments

This paper presents a tool for the visual analysis of navigation patterns of moving entities, such as users, virtual characters or vehicles in 3D virtual environments (VEs). The tool, called VU-Flow, provides a set of interactive visualizations that highlight interesting navigation behaviors of single or groups of moving entities that were the VE together or separately. The visualizations help to improve the design of VEs and to study the navigation behavior of users, e.g., during controlled experiments. Besides VEs, the proposed techniques could also be applied to visualize real-world data recorded by positioning systems, allowing one to employ VU-Flow in domains such as urban planning, transportation, and emergency response     

Performance of new participants in virtual environments: The Nottingham tool for assessment of interaction in virtual environments (NAÏVE)

There is a need for an assessment tool which reliably distinguishes levels of participant performance in virtual environments (VEs) built within virtual reality (VR) systems. Such screening might be of potential users amongst a company's staff or might be carried out by human factors experimenters prior to the start of experiments in order to provide a base-line of participant competences. The Nottingham Tool for Assessment for Interaction in Virtual Environments (NAÏVE) comprises a set of VE tasks and related tests, with appropriate performance criteria levels, covering the main aspects of navigation (viewpoint) control and object manipulation and operation. Trials with test participants enabled performance levels to be set to distinguish good, adequate and poor performers and tests to be distinguished according to whether performance in the general population is evenly spread or is skewed towards success or failure.     

Performance of a skilled motor task in virtual and real environments

Three experiments compared the performances of adult participants (three groups of 10) on a perceptuo-motor task in both real world (RW) and virtual environments (VEs). The task involved passing a hoop over a bent wire course, and three versions of the task were used: a 3-D wire course with no background, a flattened version of the 3-D course (2½-D course) with no background, and the 2½-D course with added background to provide spatial context. In all three experiments the participants had to prevent the hoop from touching the wire as they moved it. In the first experiment, the VE condition produced about 18 times more errors than the RW task. The VE 2½-D task was found to be as difficult as the 3-D, and the 2½-D with the added background produced more errors than the other two experiments. Taken together, the experiments demonstrate the difficulty of performing fine motor tasks in VEs, a phenomenon that has not been given due attention in many previous studies of motor control in VEs.     

Do challenge, task experience or computer familiarity influence the learning of historical chronology from virtual environments in 8-9 year old children?

Studies examined the potential use of VEs in teaching historical chronology to 127 children of primary school age (8-9 years). The use of passive fly-through VEs had been found, in an earlier study, to be disadvantageous with this age group when tested for their subsequent ability to place displayed sequential events in correct chronological order. All VEs in the present studies included active challenge, previously shown to enhance learning in older participants. Primary school children in the UK (all frequent computer users) were tested using UK historical materials, but no significant effect was found between three conditions (Paper, PowerPoint and VE) with minimal pre-training. However, excellent (error free) learning occurred when children were allowed greater exploration prior to training in the VE. In Ukraine, with children having much less computer familiarity, training in a VE (depicting Ukrainian history) produced better learning compared to PowerPoint, but no better than in a Paper condition. The results confirmed the benefit of using challenge in a VE with primary age children, but only with adequate prior familiarisation with the medium. Familiarity may reduce working memory load and increase children’s spatial memory capacity for acquiring sequential temporal-spatial information from virtual displays.     

Internal pricing strategies design and simulation in virtual enterprise formation

A virtual enterprise (VE) is an organization intended to cope with the rapidly changing manufacturing environment. Organization building is important in virtual domains because it has largely been affecting the success of VEs. However, the process of forming a VE is based on self-determination by the participants. This paper adopts a bargaining model under a scenario of incomplete information to formalize the formation process, considers the characteristics of the VE formation process, presents the pricing strategies for the corresponding bargaining, and verifies the correctness and validity of the pricing strategies using computer simulation. This paper breaks through the relative research that compares the formation process with partner selection from the core enterprise’s perspective and also provides the basis for the intelligent information platform of VE, whose key part is pricing software.     

Effects of virtual environment platforms on emotional responses

The goal of the current study was to investigate the effects of different virtual environment (VE) technologies (i.e., desktop, head mounted display, or fully immersive platforms) on emotional arousal and task performance. Fifty-three participants were recruited from a college population. Reactivity to stressful VEs was examined in three VE systems from desktop to high-end fully immersive systems. The experiment was a 3 (desktop system, head mounted display, and six wall system) × 2 (high- and low-stressful VE) within subject design, with self-reported emotional arousal and valence, skin conductance, task performance, presence, and simulator sickness examined as dependent variables. Replicating previous studies, the fully immersive system induced the highest sense of presence and the head mounted display system elicited the highest amount of simulator sickness. Extending previous studies, the results demonstrated that VE platforms were associated with different patterns in emotional responses and task performance. Our findings suggest that different VE systems may be appropriate for different scientific purposes when studying stress reactivity using emotionally evocative tasks.     

Performance of a skilled motor task in virtual and real environments

Three experiments compared the performances of adult participants (three groups of 10) on a perceptuo-motor task in both real world (RW) and virtual environments (VEs). The task involved passing a hoop over a bent wire course, and three versions of the task were used: a 3-D wire course with no background, a flattened version of the 3-D course (2(1/2)-D course) with no background, and the 2(1/2)-D course with added background to provide spatial context. In all three experiments the participants had to prevent the hoop from touching the wire as they moved it. In the first experiment, the VE condition produced about 18 times more errors than the RW task. The VE 2(1/2)-D task was found to be as difficult as the 3-D, and the 2(1/2)-D with the added background produced more errors than the other two experiments. Taken together, the experiments demonstrate the difficulty of performing fine motor tasks in VEs, a phenomenon that has not been given due attention in many previous studies of motor control in VEs.     

Virtual and interactive environments for work of the future

Virtual reality (VR) systems and the virtual environments (VEs) experienced within them have presented challenges to human computer interaction over many years. The sheer range of different interfaces which might be experienced and of different behaviours which might be exhibited have caused difficulties in general understanding of participants’ performance within VR/VE and in providing coherent guidance for designers. We have recently completed a European Information Society Technologies (IST) project, Virtual and Interactive Environments for Workplaces of the Future (VIEW of the Future), which has made great strides in developing improved VR systems and interaction concepts and devices, based upon good understanding of participation in VEs. Particular emphasis in the VIEW of the Future project has been upon mobility and multiple active collaboration in use of VR/VE. This paper introduces a special issue devoted to this project and overviews the project as a whole. In doing so it also reviews some of the human factors issues defined for VR/VE over the years and the contribution of VIEW of the Future to addressing these.     

Measuring the Sense of Presence and its Relations to Fear of Heights in Virtual Environments

This article describes a study in which a genuine effect of presence--the development of fear of virtual stimuli--was provoked. Using a self-report questionnaire, the sense of presence within this situation was measured. It was shown that fear increased with higher presence. The method, which involved 37 participants, was tested and validated with user tests at the Bauhaus University. A growing body of research in human-computer interface design for virtual environments (VE) concentrates on the problem of how to involve the user in the VE. This effect, usually called immersion or the sense of presence, has been the subject of much research activity. This research focuses on the influence of technical and technological parameters on the sense of presence. However, little work has been done on the effects of experienced sense of presence. One field in which a sense of presence is necessary for the successful application of VEs is the treatment of acrophobic patients. Our goals are to (a) create a theory-based self-report measurement for presence and (b) measure presence independently from specific effects to validate the measurement. The anxiety resulting from the confrontation with a virtual cliff is used to validate the measurement of presence.     

Secure resource sharing on cross-organization collaboration using a novel trust method

A virtual enterprise (VE) consists of a network of independent, geographically dispersed administrative business domains that collaborate with each other by sharing business processes and resources across enterprises to provide a value-added service to customers. Therefore, the success of a VE relies on full information transparency and appropriate resource sharing, making security and trust among subjects significant issues. Trust evaluation to ensure information security is most complicated in a VE involving cross-organization collaboration. This study presents a virtual enterprise access control (VEAC) model to enable resource sharing for collaborative operations in the VE. A scenario for authentication and authorization in the life cycle of a VE is then described to identify the main activities for controlling access. Also developed herein is a trust evaluation method based on the VEAC model to improve its security while safeguarding sensitive resources to support collaborative activities. The trust evaluation method involves two trust evaluation sub-models, one to evaluate the level of trust between two virtual enterprise roles, and another to measure the level of trust between two projects. The two sub-models support each other to make resource-sharing decisions, and are developed based on the concepts of direct, indirect, and negative trust factors. Finally, an example of measuring the trust between two subjects is demonstrated after introducing the two sub-models. The VEAC-based trust evaluation method enables the following: (1) secure resource sharing across projects and enterprises, (2) collaborative operation among participating workers, (3) increased information transparency and (4) lowered information delay in VEs.     

Tuning self-motion perception in virtual reality with visual illusions

Motion perception in immersive virtual environments significantly differs from the real world. For example, previous work has shown that users tend to underestimate travel distances in virtual environments (VEs). As a solution to this problem, researchers proposed to scale the mapped virtual camera motion relative to the tracked real-world movement of a user until real and virtual motion are perceived as equal, i.e., real-world movements could be mapped with a larger gain to the VE in order to compensate for the underestimation. However, introducing discrepancies between real and virtual motion can become a problem, in particular, due to misalignments of both worlds and distorted space cognition. In this paper, we describe a different approach that introduces apparent self-motion illusions by manipulating optic flow fields during movements in VEs. These manipulations can affect self-motion perception in VEs, but omit a quantitative discrepancy between real and virtual motions. In particular, we consider to which regions of the virtual view these apparent self-motion illusions can be applied, i.e., the ground plane or peripheral vision. Therefore, we introduce four illusions and show in experiments that optic flow manipulation can significantly affect users' self-motion judgments. Furthermore, we show that with such manipulations of optic flow fields the underestimation of travel distances can be compensated.