In the arena of software development, implementing a software design (no matter how perfect the design) is rarely done right the first time. Consequently, debugging one's own (or someone else's) software is inevitable, and tools that assist in this often-arduous task become very important with respect to reducing the cost of debugging as well as the cost of the software life cycle as a whole. Many tools exist with this aim, but all are lacking in a key area: information visualization. Applying information visualization techniques such as zooming, focus and context, or graphical representation of numeric data may enhance the visual debugging experience. To this end, drawing data structures as graphs is potentially a step in the right direction, but more must be done to maximize the value of time spent debugging and to minimize the actual amount of time spent debugging. This thesis will address some information visualization techniques that may be helpful in debugging (specifically with respect to visual debugging) and will present the results of a small pilot study intended to illustrate the potential value of such techniques. / Master of Science

Information visualization (info vis) deals with how to increase the bandwidth of effective communication between computer and human, enabling us to see more, understand more, and accomplish more. Traditionally, it deals with interaction and display techniques of visualizing often abstract data on the two-dimensional desktop. Immersive virtual environments (VEs) offer new, exciting possibilities for information visualization. Immersion gives an enhanced realistic effect, and can improve spatial understanding and orientation. By identifying or developing useful interaction techniques (ITs), we can develop VE systems for better information visualization. This thesis has two different experiments that were related to two different sides of the study of use of immersion for VEs. One of the experiments is related to abstract data visualization in an immersive VE. The other one was motivated by the need for enhancing a realistic VE with additional data. In our first experiment, our focus is on implementing overview+detail techniques in VEs. Our hypothesis is that VE-specific ITs should borrow from, but not copy existing 2D IT technique for overview +detail. We develop ITs for use in VEs and show that they are easy to use and useful using task-based usability evaluation. We develop the "jump" technique for use in this application, which can be generalized to numerous other applications. The tangible contribution of this research is Wizard, an application for infovis in VEs. Our second hypothesis is that if the data to be visualized has inherent spatial attributes, it can be visualized well in immersive virtual environments. We investigate the trends using an experiment that tests people's understanding of spatial attributes under immersive and desktop conditions. Although not statistically significant, we observed a moderate trend indicating that immersion decreases the time needed to perform a spatial information- gathering task. We believe that this area of research can be applied immediately to the applications currently being developed. / Master of Science

This thesis project set out to find and implement a comfortable way to explore vast, multidimensional datasets using interactive multiscale visualizations to combat the ever-growing information overload that the digitized world is generating. Starting at the realization that even for people not working in the fields of information visualization and data science the size of interesting datasets often outgrows the capabilities of standard spreadsheet applications such as Microsoft Excel. This project established requirements for a system to overcome this problem. In this thesis report, we describe existing solutions, related work, and in the end designs and implementation of a working tool for initial data exploration that utilizes novel multiscale visualizations to make complex coherences comprehensible and has proven successful in a practical evaluation with two case studies.