Four Easy Pieces: Development Systems for Knowledge-Based Generative Instruction
10 (1): "Part II of the Special Issue on Authoring Systems for Intelligent Tutoring Systems"
The Experimental Advanced Design Advisor (XAIDA) is a system for the
development of computer-based maintenance training. XAIDA acquires knowledge of a device
from a subject matter expert and applies common maintenance-training procedures to generate
interactive training from the description. XAIDA provides maintenance training in four areas:
the physical characteristics of a device, its theory of operation, operating and maintenance
procedures, and troubleshooting. XAIDA relies on an instructional device known as a
transaction shell, an instructional procedure applicable to particular instructional objectives of a
specific type. XAIDA employs a different transaction shell for each of the four above-
mentioned areas, and each shell employs a knowledge structure appropriate to the shell.
Semantic networks represent physical characteristics and procedures; causal reasoning schemes
represent theory of operation; and fault trees represent troubleshooting. Each shell provides a
browser that is used to present knowledge to the student and a practice environment that
promotes skill acquisition under the guidance of an intelligent tutoring system. Subject-matter
experts create device descriptions using a WYSIWYG knowledge acquisition system that
makes for extremely efficient development. This paper describes each shell in detail,
summarizes the research that has been done, and describes where XAIDA stands in relation to
other knowledge-based authoring tools.