Pattern associativity and the retrieval of semantic networks

Robert Levinson
1992 Computers and Mathematics with Applications  
Four methods for the assodative retrieval of semantic networks are described. These methods differ from those traditional approaches, such as SNEPS, in which an entire knowledge base is treated as a single network. Here the knowledge base is viewed as an organized collection of networks and is most appropriate for appUcations (such as bibliographic retrieval) in which pieces of knowledge need to be treated individually. Method I is an arbitrary fiat ordering of database graphs, Method II a
more » ... evel ordering, and Method III is a full partial order. Method IV is a novel method known as "hierarchical node descriptor method" that is based on the "refinement" method of auhgraph-isomorphism. A "pattern associativity" principle explains the development and effectiveness of each of these methods. Moving from Method I through Method IV there is a steady increase in both pattern associativity and efficiency. A theorem is proven that establishes the superiority of Method III over Method II despite the fact that Method lI is the method moat often used. A brid discussion of how parallelism may be incorporated also accompanies the description of each method. Moat of the paper applies these methods to conceptual graphs and a later section shows how the techniques can be extended to other sentantic-network formalisms. The paper concludes by showing how generalization graphs constructed through pattern associativity may also have semantic validity in the domains from which they have been derived. Sometimes it is simplicity which is hidden under what is apparently complex; sometimes on the contrary, it is simplicity which is apparent, and which conceals extremely complex realities .... No doubt, if our means of investigation became more and more penetrating, we should discover the simple beneath the complex, and then the complex from the simple, and then again the simple beneath the complex, and so on, without ever being able to predict what the last term will be. --Henri Poincare [1] 3. To present a new organizational scheme based on further evolution of this principle. 4. To outline parallel implementations of these methods. "The paper has benefited from the constructive suggestions of three anonymous reviewers of the article and the editor. Gerard Ellis provided useful references and much encouragement. Jean McKnight forrmstted several drafts and Max Coppernum helped with the introduction. Many thanks to R]ch~u~i Snyder who has produced the pictures for the article and provided critical comments throughout the final revision. 573 5T4 R. LEVINSON
doi:10.1016/0898-1221(92)90125-2 fatcat:rr4qwqxiufffhhtqs6jm3sroaa