The purpose of this study was to test the feasibility of using a model adapted from the instructional design and technology (ID&T) taxonomy model proposed by the Association for Educational Communications and Technology (AECT) Definitions and Terminology Committee to build an ID&T knowledge base. The model was tested by mapping a random sample of 152 ID&T dissertations into the three-dimensional model. (The major side of the model is divided into four areas: design, delivery, evaluation, and management. The second side divides each of these four major areas into sub-areas such as instructional design and learning theory. The third side is divided into three types of knowledge theory: research, theory, and philosophy.) Each of the selected dissertations was assigned to a specific cell within the model by two evaluators. Every cell on the research plane, except formative evaluation, had at least one dissertation; only three were mapped into the theory and philosophy planes. Two new cells were added to the original model in the process of mapping, General Delivery and Personnel Management, and four dissertations (3% of the sample) did not fit into any of the cells in the model. The only cell that showed a major increase in the percentage of dissertations from 1977 to 1988 was electronic technology. It was concluded that the model is a reasonable representation of the ID&T knowledge base, and it is suggested that articles from prominent journals should also be mapped to test the validity of the model and to better define the knowledge base for the field. (7 references) (BBM)