• DOI:10.1109/MC.1983.1654194
• Corpus ID: 16650410

What IS-A Is and Isn't: An Analysis of Taxonomic Links in Semantic Networks

@article{Brachman1983WhatII,
  title={What IS-A Is and Isn't: An Analysis of Taxonomic Links in Semantic Networks},
  author={Ronald J. Brachman},
  journal={Computer},
  year={1983},
  volume={16},
  pages={30-36}
}

• R. Brachman
• Published 1 October 1983
• Computer Science
• Computer

A was quite simple. Today, however, there are almost as many meanings for this inheritance link as there are knowledge-representation systems. Many systems for representing knowledge can be conisidered semantic networks largely becau.se they feature the notion of an explicit taxonomic hierarchy, a tree or lattice-like structure for categorizing classes of things in the world being represented. The backbone of the hierarchy is proFvided by some sort of "inheritance" link betweeni the representational objects, known as "nodes" in some systems and as "frames" in others. This link, otten called "IS-A" (also known as "IS," "SUPERC," "AKO," "SUBSET," etc.), has been perhaps the most stable element of semantic nets as they have evolved over t he yvears. Unfortunately, thi.s stability may be illusory. There are almost as many meanings for the IS-A link as there are knowledge-representation systems. In this article* we catalog the nmore common interpretations of IS-A and point out some differences between systems that, on the surface, appear very similar. Background. The idea of IS-A is quite simple. Early in the history of semantic nets, researchers observed that much representation of the world was concerned with the conceptual relations expressed in English sentences such as "John is a bachelor" and "A dog is a domesticated carnivorous mammal." That is, two predominant forms of statements handled by Al knowledge-representation systems were the predication, expressing that an individual (e.g., John) was of a certain type (e.g.,