KNACK is a knowledge acquisition tool that generates expert systems for evaluating designs of electromechanical systems. An important feature of KNACK is that it acquires knowledge from domain experts without presupposing knowledge engineering skills on their part. This is achieved by incorporating general knowledge about evaluating tasks in KNACK. Using that knowledge, KNACK builds a conceptual model of the domain through an interview process with the expert. KNACK expects the expert to communicate a portion of his knowledge as a sample report and divides the report into small fragments. It asks the expert for strategies of how to customize the fragments for different applications. KNACK generalizes the fragments and strategies, displays several instantiations of them, and the expert edits any of these that need it. The corrections motivate and guide KNACK in refining the knowledge base. Finally, KNACK examines the acquired knowledge for incompleteness and inconsistency. This process of abstraction and completion results in a knowledge base containing a large collece 20. DISTRIBUTION / AVAILABILITY OF ABSTRACT 21I ABSTRACT SECURITY CLASSIFICATION C3UNCLASSIFIE01LJNLIMITED It SAME AS RPT 0DTIC USERS 1 UNCLASSIFIED 22a. NAME OF RESPONSIBLE INOIVInUAI. 22b. TELEPHONE (Iniclude A'ea Cod)7 22c. FF;CE SV SC,.
This work explores two categories for evaluating and measuring virtual environment (VE) interfaces. One category concerns characteristics of the interface, such as its complexity and abstractness. The other catego~concerns the human capacities for understanding and using three-dimensional input/output devices. The results may help us predict the usability of VE interfaces and help us to design interfaces that are well matched to their intended users.
Usability tests comparing three different virtual environment (VE) interface designs indicate that an immersive VE is more usable than two non-irnmersive VEs for a task with search and navigation components. Three interface designs were tried in a counterbalanced within-subjects procedure with ten randomly-ordered trials for each interface design. One of the interface designs used a head-tracked, stereoscopic head-mounted display. The other two interface designs used hand-tracking and were non-immersive--the visual display appeared on a desktop monitor. Results for sixty participants doing the same task with each interface design show faster task completion times with the irnmersive design.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.