Abstract: | The history of semantic networks is almost as long as that of their parent discipline, artificial intelligence. They have formed the basis of many fascinating, yet controversial, discussions in conferences and in the literature, ranging from metaphysics through to complexity theory in computer science. Many excellent surveys of the field have been written, and yet it is our belief that none of them has examined the important link between their use as a formal scheme for knowledge representation and their more heuristic use as an informal tool for thinking. In our consideration of semantic networks as computerized tools, we will discuss three levels of abstraction that we believe can help us understand how semantic networks are used. I. |