Figure - PMC

Skip to main content

An official website of the United States government

Here's how you know

Here's how you know

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

View full-text article in PMC

. 2016 May 21;16:18. doi: 10.1186/s12861-016-0116-y

Search in PMC
Search in PubMed
View in NLM Catalog
Add to search

© Clarkson. 2016

Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.

PMC Copyright notice

Fig. 2 — Levels of complexity in semantic representation. A controlled vocabulary is a list of defined terms. A taxonomy is a controlled vocabulary with a hierarchical structure formed by is_a relationships between pairs of terms. An ontology is a taxonomy with additional relationships, such as part_of