Testbed Evaluation of Navigation and Text Display Techniques in an Information-Rich Virtual Environment
Information-Rich Virtual Environment (IRVE) is a virtual environment (VE) that is enhanced with the addition of related abstract information. Such an environment conveys rich information set that can make the VE more useful if provided with a useful interface and efficient interaction techniques. This motivates our current research goals to investigate the interface and interaction issues involved in IRVE. The fundamental question is how to access and display information in an effective way. This paper presents the first controlled experiment using a travel testbed based on our text layout taxonomy. We investigated two manipulation-based navigation techniques: Hand-Centered Object Manipulation Extending Ray0casting (HOMER) and Go-Go based navigation, and two text layout techniques; within-the-world display (WWD) and heads-up display (HUD). Four search tasks with repeated measures were performed to measure subjects performance in a densely packed environment. We found that using Go-Go based navigation combined with HUD techniques is significantly better than the other three combinations for difficulty search tasks. HUD enabled better performance than WWD and Go-Go technique enabled better performance than HOMER technique ro most of the tasks. Also users preferred the combination of Go-Go and HUD for all tasks. Such results on their own, or combined with specific application characteristics, can provide valuable design guidelines for IRVEs.