semantic network
In plain wordsA way of storing knowledge as a web of concepts joined by labeled arrows, such as 'canary — is a — bird' and 'bird — can — fly', so a program can follow the links.
A knowledge representationknowledge representation, n.: The study of how to record knowledge about objects, categories, rules and events in a precise format, so that a program can reason with it and reach conclusions nobody typed in. that encodes knowledge as a directed graph whose nodes denote concepts or individuals and whose labeled edges denote relations between them, such as is-a (subclass), instance-of and part-of. Inference proceeds by traversing links: properties attached to a general node are inherited by more specific ones, so a canary inherits 'can fly' from bird unless the link is overridden, and spreading activation outward from two nodes can find the path that connects them. Early networks lacked precise semantics — William Woods's 1975 essay 'What's in a Link' criticized their ambiguity — which led to structured successors such as KL-ONE and eventually description logicsdescription logic, n.: A family of precise logical languages for defining categories and how they relate, such as 'a parent is a person with at least one child', designed so that a computer's reasoning about them always finishes.. Knowledge graphsknowledge graph, n.: A huge web of facts stored as connections between things — 'Paris is the capital of France', 'Marie Curie won a Nobel Prize' — that computers can search, combine and reason over. and WordNetWordNet, prop. n.: A hand-made map of English vocabulary in which words sharing a meaning are bundled together and the bundles are linked — recording, say, that a dog is a kind of animal and a wheel is part of a car. are modern descendants.
Origin
Usually traced to Richard H. Richens of the Cambridge Language Research Unit, whose 1956 paper on machine translation described 'semantic nets' of concepts as a language-neutral intermediate representation. M. Ross Quillian's 1966 doctoral thesis and 1968 chapter 'Semantic Memory' turned them into a model of human memory, which Allan Collins and Quillian tested with reaction-time experiments in 1969.
Related
- knowledge representationknowledge representation, n.: The study of how to record knowledge about objects, categories, rules and events in a precise format, so that a program can reason with it and reach conclusions nobody typed in.
- frameframe, n.: In classic AI, a ready-made template for a familiar kind of thing or event, such as a kitchen or a job interview, with blanks to fill in and sensible default values.
- knowledge graphknowledge graph, n.: A huge web of facts stored as connections between things — 'Paris is the capital of France', 'Marie Curie won a Nobel Prize' — that computers can search, combine and reason over.
- description logicdescription logic, n.: A family of precise logical languages for defining categories and how they relate, such as 'a parent is a person with at least one child', designed so that a computer's reasoning about them always finishes.
- ontologyontology, n.: A carefully defined vocabulary for a subject such as medicine, spelling out each kind of thing, how kinds nest inside one another, and which connections between them are allowed.
- WordNetWordNet, prop. n.: A hand-made map of English vocabulary in which words sharing a meaning are bundled together and the bundles are linked — recording, say, that a dog is a kind of animal and a wheel is part of a car.
Sources
- Quillian, M. R. (1968). Semantic Memory. In M. Minsky (ed.), Semantic Information Processing. MIT Press.
- Woods, W. A. (1975). What's in a Link: Foundations for Semantic Networks. In D. Bobrow & A. Collins (eds.), Representation and Understanding. Academic Press.
Mentioned in
symbolic AIsymbolic AI, n.: An approach to AI that writes knowledge down as human-readable symbols and rules, such as 'every bird has wings', and reasons by manipulating them step by step instead of learning patterns from data., frameframe, n.: In classic AI, a ready-made template for a familiar kind of thing or event, such as a kitchen or a job interview, with blanks to fill in and sensible default values., knowledge graphknowledge graph, n.: A huge web of facts stored as connections between things — 'Paris is the capital of France', 'Marie Curie won a Nobel Prize' — that computers can search, combine and reason over., knowledge representationknowledge representation, n.: The study of how to record knowledge about objects, categories, rules and events in a precise format, so that a program can reason with it and reach conclusions nobody typed in., conceptual dependencyconceptual dependency, n.: A 1970s theory for representing the meaning of sentences with a small set of basic actions, so that 'John gave Mary a book' and 'Mary got a book from John' come out the same., description logicdescription logic, n.: A family of precise logical languages for defining categories and how they relate, such as 'a parent is a person with at least one child', designed so that a computer's reasoning about them always finishes., scriptscript, n.: In classic AI, a stored outline of a familiar sequence of events, such as eating at a restaurant, that helps a program understand a story by filling in what normally happens.