Ontology (computer science) - AbsoluteAstronomy.com

Computer science

Computer science or computing science is the study of the theoretical foundations of information and computation and of practical techniques for their implementation and application in computer systems...

and information science

Information science

-Introduction:Information science is an interdisciplinary science primarily concerned with the analysis, collection, classification, manipulation, storage, retrieval and dissemination of information...

, an ontology formally represents knowledge as a set of concepts within a domain

Domain of discourse

In the formal sciences, the domain of discourse, also called the universe of discourse , is the set of entities over which certain variables of interest in some formal treatment may range...

, and the relationships between those concepts. It can be used to reason about the entities within that domain and may be used to describe the domain.

In theory, an ontology is a "formal, explicit specification of a shared conceptualisation". An ontology renders shared vocabulary and taxonomy which models a domain with the definition of objects and/or concepts and their properties and relations.

Ontologies are the structural frameworks for organizing information and are used in artificial intelligence

Artificial intelligence

Artificial intelligence is the intelligence of machines and the branch of computer science that aims to create it. AI textbooks define the field as "the study and design of intelligent agents" where an intelligent agent is a system that perceives its environment and takes actions that maximize its...

, the Semantic Web

Semantic Web

The Semantic Web is a collaborative movement led by the World Wide Web Consortium that promotes common formats for data on the World Wide Web. By encouraging the inclusion of semantic content in web pages, the Semantic Web aims at converting the current web of unstructured documents into a "web of...

, systems engineering

Systems engineering

Systems engineering is an interdisciplinary field of engineering that focuses on how complex engineering projects should be designed and managed over the life cycle of the project. Issues such as logistics, the coordination of different teams, and automatic control of machinery become more...

, software engineering

Software engineering

Software Engineering is the application of a systematic, disciplined, quantifiable approach to the development, operation, and maintenance of software, and the study of these approaches; that is, the application of engineering to software...

, biomedical informatics, library science

Library science

Library science is an interdisciplinary or multidisciplinary field that applies the practices, perspectives, and tools of management, information technology, education, and other areas to libraries; the collection, organization, preservation, and dissemination of information resources; and the...

, enterprise bookmarking

Enterprise bookmarking

Enterprise bookmarking is a method for Enterprise 2.0 users to tag, organize, store, and search bookmarks of both web pages on the Internet and data resources stored in a distributed database or fileserver...

, and information architecture

Information Architecture

Information architecture is the art of expressing a model or concept of information used in activities that require explicit details of complex systems. Among these activities are library systems, Content Management Systems, web development, user interactions, database development, programming,...

as a form of knowledge representation

Knowledge representation

Knowledge representation is an area of artificial intelligence research aimed at representing knowledge in symbols to facilitate inferencing from those knowledge elements, creating new elements of knowledge...

about the world or some part of it. The creation of domain ontologies is also fundamental to the definition and use of an enterprise architecture framework.

Overview

The term ontology
Ontology
Ontology is the philosophical study of the nature of being, existence or reality as such, as well as the basic categories of being and their relations...

has its origin in philosophy

Philosophy

Philosophy is the study of general and fundamental problems, such as those connected with existence, knowledge, values, reason, mind, and language. Philosophy is distinguished from other ways of addressing such problems by its critical, generally systematic approach and its reliance on rational...

and has been applied in many different ways. The word element onto- comes from the Greek

Greek language

Greek is an independent branch of the Indo-European family of languages. Native to the southern Balkans, it has the longest documented history of any Indo-European language, spanning 34 centuries of written records. Its writing system has been the Greek alphabet for the majority of its history;...

ὤν, ὄντος « being; that which is », present participle of the verb εἰμί « be ». The core meaning within computer science

Computer science

is a model for describing the world that consists of a set of types, properties, and relationship types. Exactly what is provided around these varies, but they are the essentials of an ontology. There is also generally an expectation that there be a close resemblance between the real world and the features of the model in an ontology.

What many ontologies have in common in both computer science and in philosophy is the representation of entities, ideas, and events, along with their properties and relations, according to a system of categories. In both fields, one finds considerable work on problems of ontological relativity (e.g., Quine

Willard Van Orman Quine

Willard Van Orman Quine was an American philosopher and logician in the analytic tradition...

and Kripke

Saul Kripke

Saul Aaron Kripke is an American philosopher and logician. He is a professor emeritus at Princeton and teaches as a Distinguished Professor of Philosophy at the CUNY Graduate Center...

in philosophy, Sowa

John F. Sowa

John Florian Sowa is the computer scientist who invented conceptual graphs, a graphic notation for logic and natural language, based on the structures in semantic networks and on the existential graphs of Charles S. Peirce. He is currently developing high-level "ontologies" for artificial...

and Guarino

Nicola Guarino

Nicola Guarino is a researcher in the area of Formal Ontology for Information Systems, and the head of the Laboratory for Applied Ontology , part of the Italian National Research Council in Trento.- History :...

in computer science),, and debates concerning whether a normative

Normative

Normative has specialized contextual meanings in several academic disciplines. Generically, it means relating to an ideal standard or model. In practice, it has strong connotations of relating to a typical standard or model ....

ontology is viable (e.g., debates over foundationalism

Foundationalism

Foundationalism is any theory in epistemology that holds that beliefs are justified based on what are called basic beliefs . This position is intended to resolve the infinite regress problem in epistemology...

in philosophy, debates over the Cyc

Cyc

Cyc is an artificial intelligence project that attempts to assemble a comprehensive ontology and knowledge base of everyday common sense knowledge, with the goal of enabling AI applications to perform human-like reasoning....

project in AI). Differences between the two are largely matters of focus. Philosophers are less concerned with establishing fixed, controlled vocabularies than are researchers in computer science, while computer scientists are less involved in discussions of first principles, such as debating whether there are such things as fixed essences or whether entities must be ontologically more primary than processes.

History

Historically, ontologies arise out of the branch of philosophy

Philosophy

known as metaphysics

Metaphysics

Metaphysics is a branch of philosophy concerned with explaining the fundamental nature of being and the world, although the term is not easily defined. Traditionally, metaphysics attempts to answer two basic questions in the broadest possible terms:...

, which deals with the nature of reality – of what exists. This fundamental branch is concerned with analyzing various types or modes of existence, often with special attention to the relations between particular

Particular

In philosophy, particulars are concrete entities existing in space and time as opposed to abstractions. There are, however, theories of abstract particulars or tropes. For example, Socrates is a particular...

s and universals

Universal (metaphysics)

In metaphysics, a universal is what particular things have in common, namely characteristics or qualities. In other words, universals are repeatable or recurrent entities that can be instantiated or exemplified by many particular things. For example, suppose there are two chairs in a room, each of...

, between intrinsic and extrinsic properties

Intrinsic and extrinsic properties (philosophy)

An intrinsic property is a property that an object or a thing has of itself, independently of other things, including its context. An extrinsic property is a property that depends on a thing's relationship with other things...

, and between essence

Essence

In philosophy, essence is the attribute or set of attributes that make an object or substance what it fundamentally is, and which it has by necessity, and without which it loses its identity. Essence is contrasted with accident: a property that the object or substance has contingently, without...

and existence

Existence

In common usage, existence is the world we are aware of through our senses, and that persists independently without them. In academic philosophy the word has a more specialized meaning, being contrasted with essence, which specifies different forms of existence as well as different identity...

. The traditional goal of ontological inquiry in particular is to divide the world "at its joints" to discover those fundamental categories or kinds into which the world’s objects naturally fall.

During the second half of the 20th century, philosophers extensively debated the possible methods or approaches to building ontologies without actually building any very elaborate ontologies themselves. By contrast, computer scientists were building some large and robust ontologies, such as WordNet

WordNet

WordNet is a lexical database for the English language. It groups English words into sets of synonyms called synsets, provides short, general definitions, and records the various semantic relations between these synonym sets...

and Cyc

Cyc

, with comparatively little debate over how they were built.

Since the mid-1970s, researchers in the field of artificial intelligence

Artificial intelligence

(AI) have recognized that capturing knowledge is the key to building large and powerful AI systems. AI researchers argued that they could create new ontologies as computational model

Computational model

A computational model is a mathematical model in computational science that requires extensive computational resources to study the behavior of a complex system by computer simulation. The system under study is often a complex nonlinear system for which simple, intuitive analytical solutions are...

s that enable certain kinds of automated reasoning

Automated reasoning

Automated reasoning is an area of computer science dedicated to understand different aspects of reasoning. The study in automated reasoning helps produce software which allows computers to reason completely, or nearly completely, automatically...

. In the 1980s, the AI community began to use the term ontology to refer to both a theory of a modeled world and a component of knowledge systems. Some researchers, drawing inspiration from philosophical ontologies, viewed computational ontology as a kind of applied philosophy.

In the early 1990s, the widely cited Web page and paper "Toward Principles for the Design of Ontologies Used for Knowledge Sharing" by Tom Gruber

Tom Gruber

Thomas Robert Gruber is an American computer scientist, inventor, and entrepreneur with a focus on systems for knowledge sharing and collective intelligence...

is credited with a deliberate definition of ontology as a technical term in computer science

Computer science

. Gruber introduced the term to mean a specification of a conceptualization. That is, "An ontology is a description (like a formal specification of a program) of the concepts and relationships that can formally exist for an agent or a community of agents. This definition is consistent with the usage of ontology as set of concept definitions, but more general. And it is a different sense of the word than its use in philosophy".

According to Gruber (1993), "Ontologies are often equated with taxonomic hierarchies of classes, class definitions, and the subsumption relation, but ontologies need not be limited to these forms. Ontologies are also not limited to conservative definitions — that is, definitions in the traditional logic sense that only introduce terminology and do not add any knowledge about the world. To specify a conceptualization, one needs to state axioms that do constrain the possible interpretations for the defined terms."

Ontology components

Contemporary ontologies share many structural similarities, regardless of the language in which they are expressed. As mentioned above, most ontologies describe individuals (instances), classes (concepts), attributes, and relations. In this section each of these components is discussed in turn.

Common components of ontologies include:

Individuals: instances or objects (the basic or "ground level" objects)
Class
Class (set theory)
In set theory and its applications throughout mathematics, a class is a collection of sets which can be unambiguously defined by a property that all its members share. The precise definition of "class" depends on foundational context...

es: set
Class (set theory)
In set theory and its applications throughout mathematics, a class is a collection of sets which can be unambiguously defined by a property that all its members share. The precise definition of "class" depends on foundational context...

s, collections, concepts, classes in programming
Class (computer science)
In object-oriented programming, a class is a construct that is used as a blueprint to create instances of itself – referred to as class instances, class objects, instance objects or simply objects. A class defines constituent members which enable these class instances to have state and behavior...

, types of objects
Class (philosophy)
Philosophers sometimes distinguish classes from types and kinds. We can talk about the class of human beings, just as we can talk about the type , human being, or humanity...

, or kinds of things
Attribute
Attribute (computing)
In computing, an attribute is a specification that defines a property of an object, element, or file. It may also refer to or set the specific value for a given instance of such....

s: aspects, properties, features, characteristics, or parameters that objects (and classes) can have
Relations
Relation (mathematics)
In set theory and logic, a relation is a property that assigns truth values to k-tuples of individuals. Typically, the property describes a possible connection between the components of a k-tuple...

: ways in which classes and individuals can be related to one another
Function terms: complex structures formed from certain relations that can be used in place of an individual term in a statement
Restrictions: formally stated descriptions of what must be true in order for some assertion to be accepted as input
Rules: statements in the form of an if-then (antecedent-consequent) sentence that describe the logical inferences that can be drawn from an assertion in a particular form
Axioms: assertions (including rules) in a logical form
Logical form
In logic, the logical form of a sentence or set of sentences is the form obtained by abstracting from the subject matter of its content terms or by regarding the content terms as mere placeholders or blanks on a form...

that together comprise the overall theory that the ontology describes in its domain of application. This definition differs from that of "axioms" in generative grammar
Generative grammar
In theoretical linguistics, generative grammar refers to a particular approach to the study of syntax. A generative grammar of a language attempts to give a set of rules that will correctly predict which combinations of words will form grammatical sentences...

and formal logic
Formal logic
Classical or traditional system of determining the validity or invalidity of a conclusion deduced from two or more statements...

. In those disciplines, axioms include only statements asserted as a priori knowledge. As used here, "axioms" also include the theory derived from axiomatic statements
Events
Event (philosophy)
In philosophy, events are objects in time or instantiations of properties in objects. However, a definite definition has not been reached, as multiple theories exist concerning events.-Kim’s Property-Exemplification Account of Events:...

: the changing of attributes or relations

Ontologies are commonly encoded using ontology languages.

Domain ontologies and upper ontologies

A domain ontology (or domain-specific ontology) models a specific domain, which represents part of the world. Particular meanings of terms applied to that domain are provided by domain ontology. For example the word card has many different meanings. An ontology about the domain of poker

Poker

Poker is a family of card games that share betting rules and usually hand rankings. Poker games differ in how the cards are dealt, how hands may be formed, whether the high or low hand wins the pot in a showdown , limits on bet sizes, and how many rounds of betting are allowed.In most modern poker...

would model the "playing card

Playing card

A playing card is a piece of specially prepared heavy paper, thin cardboard, plastic-coated paper, cotton-paper blend, or thin plastic, marked with distinguishing motifs and used as one of a set for playing card games...

" meaning of the word, while an ontology about the domain of computer hardware

Computer hardware

Personal computer hardware are component devices which are typically installed into or peripheral to a computer case to create a personal computer upon which system software is installed including a firmware interface such as a BIOS and an operating system which supports application software that...

would model the "punched card

Punched card

A punched card, punch card, IBM card, or Hollerith card is a piece of stiff paper that contains digital information represented by the presence or absence of holes in predefined positions...

" and "video card

Video card

A video card, Graphics Card, or Graphics adapter is an expansion card which generates output images to a display. Most video cards offer various functions such as accelerated rendering of 3D scenes and 2D graphics, MPEG-2/MPEG-4 decoding, TV output, or the ability to connect multiple monitors...

" meanings.

An upper ontology

Upper ontology (computer science)

In information science, an upper ontology is an ontology which describes very general concepts that are the same across all knowledge domains. The most important function of an upper ontology is to support very broad semantic interoperability between a large number of ontologies accessible...

(or foundation ontology) is a model of the common objects that are generally applicable across a wide range of domain ontologies. It employs a core glossary that contains the terms and associated object descriptions as they are used in various relevant domain sets. There are several standardized upper ontologies available for use, including Dublin Core

Dublin Core

The Dublin Core metadata terms are a set of vocabulary terms which can be used to describe resources for the purposes of discovery. The terms can be used to describe a full range of web resources: video, images, web pages etc and physical resources such as books and objects like artworks...

, GFO

General Formal Ontology

The general formal ontology is an upper ontology integrating processes and objects. GFO has been developed by Heinrich Herre, Barbara Heller and collaborators in Leipzig. Although GFO provides one taxonomic tree, different axiom systems may be chosen for its modules. In this sense, GFO provides...

, OpenCyc/ResearchCyc, SUMO

Suggested Upper Merged Ontology

The Suggested Upper Merged Ontology or SUMO is an upper ontology intended as a foundation ontology for a variety of computer information processing systems. It was originally developed by the Teknowledge Corporation and now is maintained by . It is one candidate for the "standard upper ontology"...

, and DOLCE. WordNet

WordNet

, while considered an upper ontology by some, is not strictly an ontology. However, it has been employed as a linguistic tool for learning domain ontologies.

The Gellish

Gellish

Gellish is a controlled natural language, also called a formal language, in which information and knowledge can be expressed in such a way that it is computer-interpretable, as well as system-independent. Gellish is a structured subset of natural language that is suitable for information modelling...

ontology is an example of a combination of an upper and a domain ontology.

Since domain ontologies represent concepts in very specific and often eclectic ways, they are often incompatible. As systems that rely on domain ontologies expand, they often need to merge domain ontologies into a more general representation. This presents a challenge to the ontology designer. Different ontologies in the same domain can also arise due to different perceptions of the domain based on cultural background, education, ideology, or because a different representation language was chosen.

At present, merging ontologies that are not developed from a common foundation ontology is a largely manual process and therefore time-consuming and expensive. Domain ontologies that use the same foundation ontology to provide a set of basic elements with which to specify the meanings of the domain ontology elements can be merged automatically. There are studies on generalized techniques for merging ontologies, but this area of research is still largely theoretical.

Ontology engineering

Ontology engineering in computer science and information science is a new field, which studies the methods and methodologies for building ontologies: formal representations of a set of concepts within a domain and the relationships between those concepts....

(or ontology building) is a subfield of knowledge engineering

Knowledge engineering

Knowledge engineering was defined in 1983 by Edward Feigenbaum, and Pamela McCorduck as follows:At present, it refers to the building, maintaining and development of knowledge-based systems...

that studies the methods and methodologies for building ontologies. It studies the ontology development process, the ontology life cycle, the methods and methodologies for building ontologies, and the tool suites and languages that support them.

Ontology engineering aims to make explicit the knowledge contained within software applications, and within enterprises and business procedures for a particular domain. Ontology engineering offers a direction towards solving the interoperability problems brought about by semantic obstacles, such as the obstacles related to the definitions of business terms and software classes. Ontology engineering is a set of tasks related to the development of ontologies for a particular domain.

Ontology languages

An ontology language is a formal language

Formal language

A formal language is a set of words—that is, finite strings of letters, symbols, or tokens that are defined in the language. The set from which these letters are taken is the alphabet over which the language is defined. A formal language is often defined by means of a formal grammar...

used to encode the ontology. There are a number of such languages for ontologies, both proprietary and standards-based:

Common Algebraic Specification Language
Common Algebraic Specification Language
The Common Algebraic Specification Language is a general-purpose specification languagebased on first-order logic with induction. Partial functionsand subsorting are also supported....

is a general logic-based specification language developed within the IFIP working group 1.3 "Foundations of System Specifications" and functions as a de facto standard in the area of software specifications. It is now being applied to ontology specifications in order to provide modularity and structuring mechanisms.
Common logic
Common logic
Common logic is a framework for a family of logic languages, based on first-order logic, intended to facilitate the exchange and transmission of knowledge in computer-based systems....

is ISO standard 24707, a specification for a family of ontology languages that can be accurately translated into each other.
The Cyc
Cyc
Cyc is an artificial intelligence project that attempts to assemble a comprehensive ontology and knowledge base of everyday common sense knowledge, with the goal of enabling AI applications to perform human-like reasoning....

project has its own ontology language called CycL
CycL
CycL in computer science and artificial intelligence is an ontology language used by Doug Lenat's Cyc artificial intelligence project. Ramanathan V. Guha was instrumental in the design of early versions of the language. There is a close variant of CycL known as MELD.The original version of CycL was...

, based on first-order predicate calculus with some higher-order extensions.
DOGMA
DOGMA
DOGMA, short for Developing Ontology-Grounded Methods and Applications, is the name of research project in progress at Vrije Universiteit Brussel's STARLab, Semantics Technology and Applications Research Laboratory...

(Developing Ontology-Grounded Methods and Applications) adopts the fact-oriented modeling approach to provide a higher level of semantic stability.
The Gellish
Gellish
Gellish is a controlled natural language, also called a formal language, in which information and knowledge can be expressed in such a way that it is computer-interpretable, as well as system-independent. Gellish is a structured subset of natural language that is suitable for information modelling...

language includes rules for its own extension and thus integrates an ontology with an ontology language.
IDEF5
IDEF5
IDEF5 is a software engineering method to develop and maintain usable, accurate, domain ontologies...

is a software engineering
Software engineering
Software Engineering is the application of a systematic, disciplined, quantifiable approach to the development, operation, and maintenance of software, and the study of these approaches; that is, the application of engineering to software...

method to develop and maintain usable, accurate, domain ontologies.
KIF
Knowledge Interchange Format
Knowledge Interchange Format is a computer-oriented language for the interchange of knowledge among disparate computer programs.It has declarative semantics ; it is logically comprehensive Knowledge Interchange Format (KIF) is a computer-oriented language for the interchange of knowledge among...

is a syntax for first-order logic
First-order logic
First-order logic is a formal logical system used in mathematics, philosophy, linguistics, and computer science. It goes by many names, including: first-order predicate calculus, the lower predicate calculus, quantification theory, and predicate logic...

that is based on S-expression
S-expression
S-expressions or sexps are list-based data structures that represent semi-structured data. An S-expression may be a nested list of smaller S-expressions. S-expressions are probably best known for their use in the Lisp family of programming languages...

s.
Rule Interchange Format
Rule Interchange Format
The Rule Interchange Format is a W3C Recommendation. RIF is part of the infrastructure for the semantic web, along with SPARQL, RDF and OWL...

(RIF) and F-Logic
F-logic
F-logic is a knowledge representation- and ontology language. F-logic combines the advantages of conceptual modeling with object-oriented, frame-based languages and offers a declarative, compact and simple syntax, as well as the well-defined semantics of a logic-based language.Features include,...

combine ontologies and rules.
OWL
Web Ontology Language
The Web Ontology Language is a family of knowledge representation languages for authoring ontologies.The languages are characterised by formal semantics and RDF/XML-based serializations for the Semantic Web...

is a language for making ontological statements, developed as a follow-on from RDF
Resource Description Framework
The Resource Description Framework is a family of World Wide Web Consortium specifications originally designed as a metadata data model...

and RDFS, as well as earlier ontology language projects including OIL
Ontology Inference Layer
OIL can be regarded as an Ontology infrastructure for the Semantic Web. OIL is based on concepts developed in Description Logic and frame-based systems and is compatible with RDFS....

, DAML, and DAML+OIL. OWL is intended to be used over the World Wide Web
World Wide Web
The World Wide Web is a system of interlinked hypertext documents accessed via the Internet...

, and all its elements (classes, properties and individuals) are defined as RDF resources
Resource (Web)
The concept of resource is primitive in the Web architecture, and is used in the definition of its fundamental elements. The term was first introduced to refer to targets of Uniform Resource Locators , but its definition has been further extended to include the referent of any Uniform Resource...

, and identified by URI
Uniform Resource Identifier
In computing, a uniform resource identifier is a string of characters used to identify a name or a resource on the Internet. Such identification enables interaction with representations of the resource over a network using specific protocols...

s.
Semantic Application Design Language (SADL) captures a subset of the expressiveness of OWL
Web Ontology Language
The Web Ontology Language is a family of knowledge representation languages for authoring ontologies.The languages are characterised by formal semantics and RDF/XML-based serializations for the Semantic Web...

, using an English-like language entered via an Eclipse
Eclipse (software)
Eclipse is a multi-language software development environment comprising an integrated development environment and an extensible plug-in system...

Plug-in.
SBVR (Semantics of Business Vocabularies and Rules) is an OMG standard adopted in industry to build ontologies.
OBO
Open Biomedical Ontologies
Open Biomedical Ontologies is an effort to create controlled vocabularies for shared use across different biological and medical domains. As of 2006, OBO forms part of the resources of the U.S...

, a language used for biological and biomedical ontologies.
(E)MOF
Meta-Object Facility
The Meta-Object Facility is an Object Management Group standard for model-driven engineering. The official reference page may be found at OMG's website.- Overview :...

and UML
Unified Modeling Language
Unified Modeling Language is a standardized general-purpose modeling language in the field of object-oriented software engineering. The standard is managed, and was created, by the Object Management Group...

are standards of the OMG
Object Management Group
Object Management Group is a consortium, originally aimed at setting standards for distributed object-oriented systems, and is now focused on modeling and model-based standards.- Overview :...

Examples of published ontologies

Basic Formal Ontology, a formal upper ontology designed to support scientific research
BioPAX, an ontology for the exchange and interoperability of biological pathway (cellular processes) data
BMO, an e-Business Model Ontology based on a review of enterprise ontologies and business model literature
CCO (Cell Cycle Ontology), an application ontology that represents the cell cycle
CContology (Customer Complaint Ontology), an e-business ontology to support online customer complaint management
CIDOC Conceptual Reference Model, an ontology for cultural heritage
Cultural heritage
Cultural heritage is the legacy of physical artifacts and intangible attributes of a group or society that are inherited from past generations, maintained in the present and bestowed for the benefit of future generations...
COSMO, a Foundation Ontology (current version in OWL) that is designed to contain representations of all of the primitive concepts needed to logically specify the meanings of any domain entity. It is intended to serve as a basic ontology that can be used to translate among the representations in other ontologies or databases. It started as a merger of the basic elements of the OpenCyc and SUMO ontologies, and has been supplemented with other ontology elements (types, relations) so as to include representations of all of the words in the Longman dictionary defining vocabulary.
Cyc
Cyc
Cyc is an artificial intelligence project that attempts to assemble a comprehensive ontology and knowledge base of everyday common sense knowledge, with the goal of enabling AI applications to perform human-like reasoning....

, a large Foundation Ontology for formal representation of the universe of discourse.
Disease Ontology
Disease ontology
The Disease Ontology is a formal ontology of human disease. It was originally developed at Northwestern University and is associated with the Open Biomedical Ontologies Foundry....

, designed to facilitate the mapping of diseases and associated conditions to particular medical codes
DOLCE
Dolce
Dolce means "sweet" in Italian and may refer to:- Places:*Dolcè, an Italian municipality located in the Province of Verona*Dolce , a village in the Czech Republic- People :*Christine Dolce...

, a Descriptive Ontology for Linguistic and Cognitive Engineering
Dublin Core
Dublin Core
The Dublin Core metadata terms are a set of vocabulary terms which can be used to describe resources for the purposes of discovery. The terms can be used to describe a full range of web resources: video, images, web pages etc and physical resources such as books and objects like artworks...

, a simple ontology for documents and publishing
Foundational, Core and Linguistic Ontologies
Foundational Model of Anatomy
Foundational Model of Anatomy
The Foundational Model of Anatomy Ontology or the FMA, is a reference ontology for the domain of anatomy. It is a symbolic representation of the canonical, phenotypic structure of an organism; a spatial-structural ontology of anatomical entities and relations which form the physical organization of...

, an ontology for human anatomy
Friend of a Friend
FOAF (software)
FOAF is a machine-readable ontology describing persons, their activities and their relations to other people and objects. Anyone can use FOAF to describe him or herself...

, an ontology for describing persons, their activities and their relations to other people and objects
Gene Ontology
Gene Ontology
The Gene Ontology, or GO, is a major bioinformatics initiative to unify the representation of gene and gene product attributes across all species...

for genomics
Genomics
Genomics is a discipline in genetics concerning the study of the genomes of organisms. The field includes intensive efforts to determine the entire DNA sequence of organisms and fine-scale genetic mapping efforts. The field also includes studies of intragenomic phenomena such as heterosis,...
Gellish English dictionary
Gellish English dictionary
The Gellish English Dictionary-Taxonomy is an example of an open-source “smart” electronic dictionary, which concepts are arranged in a subtype-supertype hierarchy, thus forming a taxonomy. The dictionary-taxonomy is a machine readable...

, an ontology that includes a dictionary and taxonomy that includes an upper ontology and a lower ontology that focusses on industrial and business applications in engineering, technology and procurement. See also Gellish as Open Source
Open source
The term open source describes practices in production and development that promote access to the end product's source materials. Some consider open source a philosophy, others consider it a pragmatic methodology...

project on SourceForge.
Geopolitical ontology
Geopolitical ontology
A geopolitical ontology is a mechanism to describe, manage and exchange data related to geopolitical entities such as countries, territories, regions and other similar areas.-Definitions and examples:...

, an ontology describing geopolitical information created by Food and Agriculture Organization
Food and Agriculture Organization
The Food and Agriculture Organization of the United Nations is a specialised agency of the United Nations that leads international efforts to defeat hunger. Serving both developed and developing countries, FAO acts as a neutral forum where all nations meet as equals to negotiate agreements and...

(FAO). The geopolitical ontology includes names in multiple languages (English, French, Spanish, Arabic, Chinese, Russian and Italian); maps standard coding systems (UN, ISO, FAOSTAT, AGROVOC, etc.); provides relations among territories (land borders, group membership, etc.); and tracks historical changes. In addition, FAO provides web services (http://www.fao.org/countryprofiles/webservices.asp?lang=en) of geopolitical ontology and a module maker (http://www.fao.org/countryprofiles/geoinfo/modulemaker/index.html) to download modules of the geopolitical ontology into different formats (RDF, XML, and EXCEL). See more information on the FAO Country Profiles
FAO Country Profiles
The FAO Country Profiles is a multilingual web portal which repackages the Food and Agriculture Organization of the United Nations vast archive of information on its global activities in agriculture and food security in a single area and catalogues it exclusively by country and thematic areas.The...

geopolitical ontology web page (http://www.fao.org/countryprofiles/geoinfo.asp?lang=en).
GOLD, General Ontology for Linguistic Description
Descriptive linguistics
In the study of language, description, or descriptive linguistics, is the work of objectively analyzing and describing how language is spoken by a group of people in a speech community...
GUM (Generalized Upper Model), a linguistically motivated ontology for mediating between clients systems and natural language technology
IDEAS Group
IDEAS Group
The IDEAS Group is the International Defence Enterprise Architecture Specification for exchange Group. The deliverable of the project is a data exchange format for military Enterprise Architectures. The scope is four nation and covers MODAF , DoDAF , and the Australian Defence Architecture...

, a formal ontology for enterprise architecture being developed by the Australian, Canadian, UK and U.S. Defence Depts.
Linkbase, a formal representation of the biomedical domain, founded upon Basic Formal Ontology.
LPL, Lawson Pattern Language
Modular Unified Tagging Ontology (MUTO), an ontology for tagging and folksonomies that unifies core concepts from other tagging ontologies in one consistent schema
Plant Ontology for plant structures and growth/development stages, etc.
NIFSTD Ontologies from the Neuroscience Information Framework
Neuroscience Information Framework
The Neuroscience Information Framework is a repository of global neuroscience web resources, including experimental, clinical, and translational neuroscience databases, knowledge bases, atlases, and genetic/genomic resources.-Description:...

: a modular set of ontologies for the neuroscience domain. See http://neuinfo.org
OBO Foundry
OBO Foundry
The Open Biomedical Ontologies Foundry is a collaborative experiment involving developers of science-based ontologies...

, a suite of interoperable reference ontologies in biomedicine
Ontology for Biomedical Investigations
Ontology for Biomedical Investigations
The Ontology for Biomedical Investigations is an open access, integrated ontology for the description of biological and clinical investigations. OBI provides a model for the design of an investigation, the protocols and instrumentation used, the materials used, the data generated and the type of...

, an open access, integrated ontology for the description of biological and clinical investigations
OMNIBUS Ontology, an ontology of learning, instruction, and instructional design
Plant Ontology for plant structures and growth/development stages, etc.
POPE, Purdue Ontology for Pharmaceutical Engineering
PRO, the Protein Ontology of the Protein Information Resource, Georgetown University.
Program abstraction taxonomy program abstraction taxonomy
Protein Ontology for proteomics
Proteomics
Proteomics is the large-scale study of proteins, particularly their structures and functions. Proteins are vital parts of living organisms, as they are the main components of the physiological metabolic pathways of cells. The term "proteomics" was first coined in 1997 to make an analogy with...
Suggested Upper Merged Ontology
Suggested Upper Merged Ontology
The Suggested Upper Merged Ontology or SUMO is an upper ontology intended as a foundation ontology for a variety of computer information processing systems. It was originally developed by the Teknowledge Corporation and now is maintained by . It is one candidate for the "standard upper ontology"...

, a formal upper ontology
Systems Biology Ontology (SBO), for computational models in biology
SWEET, Semantic Web for Earth and Environmental Terminology
ThoughtTreasure
ThoughtTreasure
ThoughtTreasure is a commonsense knowledge base and architecture for natural language processing.It contains both declarative and proceduralknowledge.-Declarative knowledge:ThoughtTreasure's knowledge baseconsists of concepts, which are...

ontology
TIME-ITEM
TIME-ITEM
TIME-ITEM is an ontology of Topics that describes the content of undergraduate medical education. TIME is an acronym for "Topics for Indexing Medical Education"; ITEM is an acronym for "Index de thèmes pour l’éducation médicale." Version 1.0 of the taxonomy has been released and the web...

, Topics for Indexing Medical Education
UMBEL
UMBEL
UMBEL, short for Upper Mapping and Binding Exchange Layer, is an extracted subset of OpenCyc, providing the Cyc data in an RDF ontology based on SKOS and OWL 2...

, a lightweight reference structure of 20,000 subject concept classes and their relationships derived from OpenCyc
WordNet
WordNet
WordNet is a lexical database for the English language. It groups English words into sets of synonyms called synsets, provides short, general definitions, and records the various semantic relations between these synonym sets...

, a lexical reference system
YAMATO, Yet Another More Advanced Top-level Ontology

The W3C Linking Open Data Community Project coordinates attempts to converge different ontologies into worldwide Data Web

Data Web

Data Web refers to a government open source project that was started in 1995 to develop open source framework that networks distributed statistical databases together into a seamless unified virtual data warehouse.Originally funded by the U.S...

Ontology libraries

The development of ontologies for the Web has led to the emergence of services providing lists or directories of ontologies with search facility. Such directories have been called ontology libraries.

The following are static libraries of human-selected ontologies.

COLORE is an open repository of first-order ontologies in Common Logic
Common logic
Common logic is a framework for a family of logic languages, based on first-order logic, intended to facilitate the exchange and transmission of knowledge in computer-based systems....

with formal links between ontologies in the repository.
DAML Ontology Library maintains a legacy of ontologies in DAML.
Protege Ontology Library contains a set of OWL, Frame-based and other format ontologies.
SchemaWeb is a directory of RDF schemata expressed in RDFS, OWL and DAML+OIL.

The following are both directories and search engines. They include crawlers searching the Web for well-formed ontologies.

OBO Foundry / Bioportal (ontology repository of NCBO) is a suite of interoperable reference ontologies in biology and biomedicine.
OntoSelect Ontology Library offers similar services for RDF/S, DAML and OWL ontologies.
Ontaria is a "searchable and browsable directory of semantic web data" with a focus on RDF vocabularies with OWL ontologies. (NB Project "on hold" since 2004).
Swoogle
Swoogle
Swoogle is a search engine for Semantic Web ontologies, documents, terms and data published on the Web. Swoogle employs a system of crawlers to discover RDF documents and HTMLdocuments with embedded RDF content...

is a directory and search engine for all RDF resources available on the Web, including ontologies.

Examples of applications using ontology engines

SAPPHIRE (Health care)
SAPPHIRE (Health care)
The Situational Awareness and Preparedness for Public Health Incidences and Reasoning Engines is a semantics-based health information system capable of tracking and evaluating situations and occurrences that may affect public health. It was developed in 2004 by Dr...

or Situational Awareness and Preparedness for Public Health Incidences and Reasoning Engines is a semantics
Semantics
Semantics is the study of meaning. It focuses on the relation between signifiers, such as words, phrases, signs and symbols, and what they stand for, their denotata....

-based health information system capable of tracking and evaluating situations and occurrences that may affect public health
Public health
Public health is "the science and art of preventing disease, prolonging life and promoting health through the organized efforts and informed choices of society, organizations, public and private, communities and individuals" . It is concerned with threats to health based on population health...

.

External links

Knowledge Representation at Open Directory Project
Library of ontologies
GoPubMed using Ontologies for searching

Standardization of Ontologies

The source of this article is wikipedia, the free encyclopedia. The text of this article is licensed under the GFDL.

Overview

History

Ontology components

Domain ontologies and upper ontologies

Ontology engineering

Ontology languages

Examples of published ontologies

Ontology libraries

Examples of applications using ontology engines

See also

Further reading

External links