Whereas interactive dynamic visualization tools have been successfully developed and used for teaching some topics in computational theory (CT), there remains a noticeable lack of such tools for teaching NP-completeness which continues to be widely taught using paper-and-pencil methods. Despite its important theoretical and practical value, NP-completeness-and mapping reductions in NP-completeness in particular-tends to be a challenging concept for CT students to understand. We present an open-source web app called Redux that provides a dynamic interactive user interface atop a practical knowledge base of NP-complete problems, reductions, and solution algorithms. A key feature of the interface is the visualization of arbitrary problem instances, mapping reductions, solutions, and gadgets-including those reachable via transitivity. The web app is designed to make the knowledge base extensible, allowing students to contribute and compare their reductions and solutions to those already available. Two surveys were administered, with respondents overwhelmingly indicating that Redux helped them to better understand mapping reductions; that they would prefer using Redux to solve similar problems manually; and that Redux makes learning NP-complete reductions more enjoyable. Redux is accessible online via https://redux.portneuf.cose.isu.edu/.

In the real world, prior research in the field of perception and action has shown that individuals visually perceive objects differently based on their actual performance of an action on those objects, especially for sporting activities. For example, a golfer who performs well on putting a ball into the hole, will perceive that ball as larger (easier to hit) and the hole as larger (easier to put the ball in). We asked the following research question, can manipulation of visual perception of objects influence actual performance in the real world? Virtual objects are easily manipulated in Virtual Reality environments, therefore we investigated the use of Virtual Reality training where the properties of objects, such as size, were manipulated to influence perception on a golf putting task. In this paper, we present the results of our experimental user study. Putting performance increased after virtual reality training exposure when virtual objects were larger (perceived as easier to hit) and decreased when virtual objects were smaller (more difficult to hit). Our research has the potential to broaden the study of how virtual reality training can be used to improve sports training in a unique way.

This paper presents a novel interaction technique to combine multiple inputs and output modalities with a 3D printed open disc which is tracked and augmented with a virtual information. Props have been used in virtual and augmented environments to provide tangible associations to virtual elements. When used in a larger immersive environment or where a user is walking around, users may not have the capability to set these objects/props down or are limited to the number of hands, so users are reduced to the capability of using only two props or controllers. In our technique, users can instead use their body to store and organize the virtual objects associated with tangible props by physically hanging them on or attaching them to the body. This type of interaction is well-suited for both immersive visualizations and immersive virtual environments. In this paper, we present the results of an experimental evaluation of our Body Prop Interaction technique for each type of immersive environment and corresponding task type, demonstrating more effective usage in each scenario than a joystick or gesture-based interaction.

Prior work has shown that visual cues are more dominant than tactile cues for static objects. When texture and material properties are added, the reverse is true. However, it is not well understood which cues play a role in perceiving these textures when objects are moving. In this paper, we present an evaluation investigating speed and angular direction mismatch between visual and tactile information while objects are moving. Our results show that when objects are stationary or moving slowly, the sense of touch dominates visual cues; but as the speed increases, visual cues dominate tactile cues. When tactile and visual cues were not matching for moving virtual objects, visual cues were more dominant when the virtual objects moved at angles less than 30 degrees different than the tactile feedback in either direction. Therefore, potentially a 1D directional haptic device with physical texture substitutions may be able to convey sufficient realism when touching virtual objects that are moving faster than 4-8cm/s and with a difference in angular direction of 30 degrees or less. In this paper, we also present the limitations of this work and outline a research agenda for future investigation of visual and tactile cue dominance for perceiving textures of virtual objects moving in a virtual environment.

Immersive Visualizations of 3-dimensional scientific data pose unique interaction challenges. One challenge is to be able to interact with the visual volumetric representations of data using direct manipulation in a way that facilitates exploration and discovery, yet maintains data relationships. In this paper, we present Body-Prop Interaction, a novel tangible multimodal interface for immersive visualizations. Our interaction technique combines multiple input and output modalities with 3D printed open discs that are tracked and augmented with virtual information. To demonstrate our technique, we implemented interactive tasks for a volume visualization of graphite billet data. While demonstrated for this type of data visualization, our novel interaction technique has the potential to be used to interact with other types of augmented and virtual reality.