One of the greatest problems facing researchers in the sub field of Artificial Intelligence known as Intelligent Tutoring Systems (ITS) is the selection of a knowledge base designs that will facilitate the modification of the knowledge base. The Class-Entity-Relationship-Attribute (CERA), proposed by R. P. Brazile, holds certain promise as a more generic knowledge base design framework upon which can be built robust and efficient ITS. This study has a twofold purpose. The first is to demonstrate that a CERA knowledge base can be constructed for an ITS on a subset of the domain of Cretaceous paleontology and function as the "expert module" of the ITS. The second is to test the validity of the ideas that students guided through a lesson learn more factual knowledge, while those who explore the knowledge base that underlies the lesson through query at their own pace will be able to formulate their own integrative knowledge from the knowledge gained in their explorations and spend more time on the system. This study concludes that a CERA-based system can be constructed as an effective teaching tool. However, while an ITS - treatment provides for statistically significant gains in achievement test scores, the type of treatment seems …

This thesis describes a set of computer program control structures which permits the application of certain structured programming techniques to the IBM/360 assembly language (ALC). The control structures are implemented by programmerdefined instructions known as macros. A history of computer software is presented, providing a basis for the emergence of structured programming. A survey of the major concepts of structured programming with special attention to control structures and their significance to structured programming follows. The macros developed in this study include DO, ENDDO, LEAVE, CASE, and ENDCASE. They provide a looping control structure, a loop-escape construct, and a selective control structure. Examples of usage are given.