Analysis domain model for shared virtual environments

The field of shared virtual environments, which also encompasses online games and social 3D environments, has a system landscape consisting of multiple solutions that share great functional overlap. However, there is little system interoperability between the different solutions. A shared virtual environment has an associated problem domain that is highly complex raising difficult challenges to the development process, starting with the architectural design of the underlying system. This paper has two main contributions. The first contribution is a broad domain analysis of shared virtual environments, which enables developers to have a better understanding of the whole rather than the part(s). The second contribution is a reference domain model for discussing and describing solutions - the Analysis Domain Model

Eye Tracking and Studying Examples: How Novices and Advanced Learners Study SQL Examples

Eye tracking provides information about a user’s eye gaze movements. For many years, eye tracking has been used in Human Computer Interaction (HCI) research. Similarly, research on computerised educational systems also relies heavily on students’ interactions with systems, and therefore eye tracking has been used to study and improve learning. We have recently conducted several studies on using worked examples in addition to scaffolded problem solving. The goal of the project reported in this paper was to investigate how novices and advanced students learn from examples. The study was performed in the context of SQL-Tutor, a mature Intelligent Tutoring System (ITS) that teaches SQL. We propose a new technique to analyse eye-gaze patterns named EGPA. In order to comprehend an SQL example, students require the information about tables’ names and their attributes which are available in a database schema. Thus, if students paid attention to the database schema, they would understand SQL examples more easily. We analysed students’ eye movement data from different perspectives, and found that advanced students paid more attention to database schema than novices. In future work, we will use the findings from this study to provide proactive feedback or individualised amounts of information

Exploring Human Computer Interaction and its Implications on Modeling for Individuals with Disabilities

Computers provide an interface to the world for many individuals with disabilities and without effective computer access, quality of life may be severely diminished. As a result of this dependence, optimal human computer interaction (HCI) between a user and their computer is of paramount importance. Optimal HCI for individuals with disabilities relies on both the existence of products which provide the desired functionality and the selection of appropriate products and training methods for a given individual. From a product availability standpoint, optimal HCI often depends on modeling techniques used during the development process to evaluate a design, assess usability and predict performance. Computer access evaluations are often too brief in duration and depend on the products present at the site of the evaluation. Models could assist clinicians in dealing with the problems of limited time with clients, limited products for the client to trial, and the seemingly unlimited system configurations available with many potential solutions. Current HCI modeling techniques have been developed and applied to the performance of able-bodied individuals. Research concerning modeling performance for individuals with disabilities has been limited. This study explores HCI as it applies to both able-bodied and individuals with disabilities. Eleven participants (5 able-bodied / 6 with disabilities) were recruited and asked to transcribe sentences presented by a text entry interface supporting word prediction with the use of an on-screen keyboard while time stamped keystroke and eye fixation data was collected. Data was examined to identify sequences of behavior, performance changes based on experience, and performance differences between able-bodied and participants with disabilities. The feasibility of creating models based on the collected data was explored. A modeling technique must support selection from multiple sequences of behavior to perform a particular type of action and variation in execution time for primitive operations in addition to handling errors. The primary contributions made by this study were knowledge gained relative to the design of the test bench and experimental protocol

Head-tracked stereo viewing with two-handed 3D interaction for animated character construction

In this paper, we demonstrate a new interactive 3D desktop metaphor based on two-handed 3D direct manipulation registered with head-tracked stereo viewing. In our configuration, a six-degree-of-freedom head-tracker and CrystalEyes shutter glasses are used to produce stereo images that dynamically follow the user head motion. 3D virtual objects can be made to appear at a fixed location in physical space which the user may view from different angles by moving his head. The user interacts with the simulated 3D environment using both hands simultaneously. The left hand, controlling a Spaceball, is used for 3D navigation and object movement, while the right hand, holding a 3D mouse, is used to manipulate through a virtual tool metaphor, the objects appearing in front of the screen because of negative parallax. In this way, both incremental and absolute interactive input techniques are provided by the system. Hand-eye coordination is made possible by registration between virtual and physical space, allowing a variety of complex 3D tasks to be performed more easily and more rapidly than is possible using traditional interactive techniques. The system has been tested using both Polhemus Fastrak and Logitech ultrasonic input devices for tracking the head and 3D mouse.197-206Pubblicat