Semantic Network (Relational Vocabularies)

Definition, description and example of a semantic network

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Semantic Network (Relational Vocabulary)


A type of relational controlled vocabulary consisting of lists of values/concepts and directed relationships.


Semantic networks can be thought of as super-thesauri. Each network can be represented in a directed graph of concept nodes connected by relations established in the NISO standard, along with additional relations such as whole-part, cause-effect, or parent-child relationships. Semantic networks tend to deal more in abstractions than concrete terminology.

A finite list of relations used in semantic networks does not exist. Semantic network relations can extend to provenance (parent-child), genesis (cause-effect) and complexity (whole-part). There are also relations for opposites, antonyms, complementary concepts, possessive, passive, and others. This is in stark contrast to the clear articulation of a finite set of relations (largely based on scope), which are articulated in ANSI/NISO Z39.19 - 2003 for thesauri.

Information technology experts tend to use semantic networks to establish complex search interfaces, which can help a user locate the most appropriate results based on the search term. Since semantic networks describe complex relationships, the search interface can be programmed to interpret the user entry into various nodes, which are included in a semantic network. The resulting search is more exhaustive than that provided by a multi-level set of values, because the system can be set up to return results from different levels or categories based upon relations.

Note: There is extensive research about the development and use of semantic networks in the fields of linguistics, psychology, and philosophy.


Example of a simple semantic network

This very simple diagram of a semantic network illustrates the directed nature of relationships. For example, using this diagram, you can make the statement "A fish is an animal that lives in the water." Or, "A bear is a mammal (a type of animal with a vertebra) that has fur."

Suggested Citation

Neiswender, C. 2011. "Semantic Network (Relational Vocabularies)." In The MMI Guides: Navigating the World of Marine Metadata. Accessed December 11, 2019.