Sabarish V. Babu

Evaluation of the Cognitive Effects of Travel Technique in Complex Real and Virtual Environments

We report a series of experiments conducted to investigate the effects of travel technique on information gathering and cognition in complex virtual environments. In the first experiment, participants completed a non-branching multilevel 3D maze at their own pace using either real walking or one of two virtual travel techniques. In the second experiment, we constructed a real-world maze with branching pathways and modeled an identical virtual environment. Participants explored either the real or virtual maze for a predetermined amount of time using real walking or a virtual travel technique. Our results across experiments suggest that for complex environments requiring a large number of turns, virtual travel is an acceptable substitute for real walking if the goal of the application involves learning or reasoning based on information presented in the virtual world. However, for applications that require fast, efficient navigation or travel that closely resembles real-world behavior, real walking has advantages over common joystick-based virtual travel techniques.

Can Immersive Virtual Humans Teach Social Conversational Protocols

We investigated the effects of using immersive virtual humans to teach users social conversational verbal and non-verbal protocols in south Indian culture. The study was conducted using a between-subjects experimental design, and compared instruction and interactive feedback from immersive virtual humans against instruction based on a written study guide with illustrations of the social protocols. Participants were then tested on how well they learned the social conversational protocols by exercising the social conventions in front of videos of real people. The results of our study suggest that participants who trained with the virtual humans performed significantly better than the participants who studied from literature.

Comparison of Travel Techniques in a Complex, Multi-Level 3D Environment

This paper reports on a study that compares three different methods of travel in a complex, multi-level virtual environment using a between-subjects design. A real walking travel technique was compared to two common virtual travel techniques. Participants explored a two-story 3D maze at their own pace and completed four post-tests requiring them to remember different aspects of the environment. Testing tasks included recall of objects from the environment, recognition of objects present and not present, sketching of maps, and placing objects on a map. We also analyzed task completion time and collision data captured during the experiment session. Participants that utilized the real walking technique were able to place more objects correctly on a map, completed the maze faster, and experienced fewer collisions with the environment. While none of the conditions outperformed each other on any other tests, our results indicate that for tasks involving the naive exploration of a complex, multi-level 3D environment, the real walking technique supports a more efficient exploration than common virtual travel techniques. While there was a consistent trend of better performance on our measures for the real walking technique, it is not clear from our data that the benefits of real walking in these types of environments always justify the cost and space trade-offs of maintaining a wide-area tracking system

“What would you like to talk about?” an evaluation of social conversations with a virtual receptionist

We describe an empirical study of Marve, a virtual receptionist located at the entrance of our research laboratory. Marve engages with lab members and visitors in natural face-to-face communication, takes and delivers messages, tells knock-knock jokes, conducts natural small talk on movies, and discusses the weather. In this research, we investigate the relative popularity of Marves social conversational capabilities and his role-specific messaging tasks, as well as his perceived social characteristics. Results indicate that users are interested in interacting with Marve, use social conversational conventions with Marve, and perceive and describe him as a social entity.

Dancing alice: exploring embodied pedagogical strategies for learning computational thinking

n this paper, we introduce an embodied pedagogical approach for learning computational concepts, utilizing computational practices, and developing computational perspectives. During a five-week pilot, a group of students spent after-school time learning the basic elements of dance and then using them to program three-dimensional characters that could perform. Throughout the pilot, we found students consistently standing up in front of their computers and using their bodies to think through the actuation of their characters. Preliminary results suggest that designing a virtual-physical dance performance is a motivating and engaging social context in which to introduce students, especially girls, to alternative applications in computing.

An Immersive Virtual Peer for Studying Social Influences on Child Cyclists' Road-Crossing Behavior

The goal of our work is to develop a programmatically controlled peer to bicycle with a human subject for the purpose of studying how social interactions influence road-crossing behavior. The peer is controlled through a combination of reactive controllers that determine the gross motion of the virtual bicycle, action-based controllers that animate the virtual bicyclist and generate verbal behaviors, and a keyboard interface that allows an experimenter to initiate the virtual bicyclists actions during the course of an experiment. The virtual bicyclists repertoire of behaviors includes road following, riding alongside the human rider, stopping at intersections, and crossing intersections through specified gaps in traffic. The virtual cyclist engages the human subject through gaze, gesture, and verbal interactions. We describe the structure of the behavior code and report the results of a study examining how 10- and 12-year-old children interact with a peer cyclist that makes either risky or safe choices in selecting gaps in traffic. Results of our study revealed that children who rode with a risky peer were more likely to cross intermediate-sized gaps than children who rode with a safe peer. In addition, children were significantly less likely to stop at the last six intersections after the experience of riding with the risky than the safe peer during the first six intersections. The results of the study and childrens reactions to the virtual peer indicate that our virtual peer framework is a promising platform for future behavioral studies of peer influences on childrens bicycle riding behavior.

Effects of calibration to visual and haptic feedback on near-field depth perception in an immersive virtual environment

Distances are regularly underestimated in immersive virtual environments (IVEs) [Witmer and Kline 1998; Loomis and Knapp 2003]. Few experiments, however, have examined the ability of calibration to overcome distortions of depth perception in IVEs. This experiment is designed to examine the effect of calibration via haptic and visual feedback on distance estimates in an IVE. Participants provided verbal and physical reach responses to target distances presented during three sessions; a baseline measure without feedback, a calibration session with visual and haptic feedback, and finally a post-calibration session without feedback. Feedback was shown to calibrate distance estimates within an IVE. Discussion focused on the possibility that costly solutions and research endeavors seeking to remedy the compression of distances may become less necessary if users are simply given the opportunity to use manual activity to calibrate to the IVE.

An evolving multi-agent scenario generation framework for simulations in preventive medicine education

We describe the design, implementation and evaluation of a novel multi-agent scenario generation framework for interactive virtual reality simulations towards preventive medicine education. Our scenario generation framework is based on recordings of human movements from a distributed sensor networks deployed in a real-world physical setting. The components of our framework include the generation of unique virtual agent behaviors from the sensor data, and algorithms for the generation of low level or gross movement behaviors such as path determination, directional traffic flows, collision avoidance and overtaking. The framework also includes the generation of high level fine actions for multi-agents such as techniques for interactive activities in pedagogical scenarios based on environment and temporal triggers. We applied our multi-agent scenario generation framework in an interactive simulation for hand hygiene education, and conduct an initial usability study to assess the educational benefits of the simulation to nursing students and evaluated the performance characteristics of our framework. Results of our quantitative and qualitative evaluations suggest that our framework was robust in creating engaging, compelling, and realistic interactive training scenarios with multiple virtual agents in simulated hospital situations.

A Virtual Peer for Investigating Social Influences on Children's Bicycling

The goal of our work is to develop a programmatically controlled peer to ride with a human subject for the purpose of studying how social interactions influence riding behavior. The peer is controlled through a combination of reactive controllers that determine the gross motion of the virtual bicycle, action-based controllers that animate the virtual bicyclist and generate verbal behaviors, and a keyboard interface that allows an experimenter to initiate the virtual bicyclists actions during the course of an experiment. The virtual bicyclists repertoire of behaviors includes road following, riding alongside the human rider, stopping at intersections, and crossing intersections through specified gaps. The virtual cyclist engages the human subject through gaze, gesture, and verbal interactions. We describe the structure of the behavior code and report the results of a pilot study examining how 10- and 12-year-old children interact with a peer cyclist. Results of the pilot study showed that the presence of the peer had a significant influence on the size of the gaps taken as well as time left to spare between the participant and the trailing car in the crossed gap.

An Empirical Evaluation of Visuo-Haptic Feedback on Physical Reaching Behaviors During 3D Interaction in Real and Immersive Virtual Environments

In an initial study, we characterized the properties of human reach motion in the presence or absence of visuo-haptic feedback in real and Immersive Virtual Environments (IVEs) or virtual reality within a participant’s maximum arm reach. Our goal is to understand how physical reaching actions to the perceived location of targets in the presence or absence of visuo-haptic feedback are different between real and virtual viewing conditions. Typically, participants reach to the perceived location of objects in the three-dimensional (3D) environment to perform selection and manipulation actions during 3D interaction in applications such as virtual assembly or rehabilitation. In these tasks, participants typically have distorted perceptual information in the IVE as compared to the real world, in part due to technological limitations such as minimal visual field of view, resolution, latency, and jitter. In an empirical evaluation, we asked the following questions: (i) how do the perceptual differences between virtual and real world affect our ability to accurately reach to the locations of 3D objects, and (ii) how do the motor responses of participants differ between the presence or absence of visual and haptic feedback? We examined factors such as velocity and distance of physical reaching behavior between the real world and IVE, both in the presence or absence of visuo-haptic information. The results suggest that physical reach responses vary systematically between real and virtual environments, especially in situations involving the presence or absence of visuo-haptic feedback. The implications of our study provide a methodological framework for the analysis of reaching motions for selection and manipulation with novel 3D interaction metaphors and to successfully characterize visuo-haptic versus non-visuo-haptic physical reaches in virtual and real-world situations.