Computer science / information systems · BEGINNER LESSON
Ontology
In computer science, an ontology is a machine-readable representation of a domain’s shared view, usually organized as concepts and the relationships among them. It can act as a formal schema for structuring data and supporting reasoning or common understanding.
What it is
In these sources, ontology means a computer-science representation of a domain’s consensus view, not the philosophical study of existence. It organizes concepts, classes, instances, properties, and relations so a system can use shared meanings for symbols and data. In practical terms, an ontology can be used to support common understanding, data modeling, and reasoning in software systems.
[1] Utilization of Ontology to Develop Artificial Intelligence ... - PMC [2] Ontology and Information Systems [3] Scientific knowledge graph and ontology generation using ...
What is measured or represented
An ontology does not measure a physical quantity like mass or temperature. Instead, it represents what concepts exist in a domain, how those concepts are related, and how words or symbols should map to those concepts. In knowledge graphs, it can provide a high-level schema that defines allowed relationships and a standardized vocabulary for the graph data.
[2] Ontology and Information Systems [3] Scientific knowledge graph and ontology generation using ...
How it works
The sources describe ontologies as built from concepts and semantic relationships. A common backbone is an isA hierarchy, also called a taxonomy, where broader categories are divided into more specific ones. Ontologies may also include relations, properties, rules, and axioms. This structure helps systems combine heterogeneous data sources, share meaning across formats, and support semantic interoperability and inference.
[1] Utilization of Ontology to Develop Artificial Intelligence ... - PMC [2] Ontology and Information Systems [3] Scientific knowledge graph and ontology generation using ...
Where it is useful
The excerpts emphasize healthcare and scientific data. In healthcare, ontologies help integrate diverse clinical data, improve analysis, and support decision-making, diagnosis, and treatment. In scientific information modeling, ontologies strengthen knowledge graphs by representing more complex hierarchies and relationships than triples alone can capture.
[1] Utilization of Ontology to Develop Artificial Intelligence ... - PMC [3] Scientific knowledge graph and ontology generation using ...
Limitations
The sources also note important limits. An ontology is only as good as the concepts and relationships it includes, so missing clinically important concepts or temporal or spatial relations can reduce usefulness. Poor methodology, weak validation, and lack of experts who know both the domain and ontology design are further constraints. Building domain-specific ontologies can be time-consuming and labor-intensive.
[1] Utilization of Ontology to Develop Artificial Intelligence ... - PMC [2] Ontology and Information Systems [3] Scientific knowledge graph and ontology generation using ...
SEE THE IDEA
Ontology in a knowledge model
The classes or categories that describe the subject area.
Links such as isA, properties, and other relationships between concepts.
Standardized terms that different systems can interpret in the same way.
Uses the ontology as a schema for organizing data and supporting reasoning.
Concepts are linked by semantic relations to create a shared vocabulary that can structure a knowledge graph or other software model.
An ontology turns domain ideas into structured, shared meanings that a computer can use.
TRY IT YOURSELF
Test your understanding
Choose an answer, then check the explanation.
PUT IT TOGETHER
Match each concept to its meaning
Drag a label onto its description, or select a label and then select a description. This also works with a keyboard.
4 pairs to match
Sources and further reading
This general lesson was generated from public source material. It explains a concept; it does not interpret a private paper or provide medical advice.