Is a hot dog a sandwich?

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Ontologies

Na’Shea Wiesner and Lucy WilliamsNovember 27, 2017

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Learning Objectives

• Definition of an Ontology

• Ontology Development

• Applications

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What is an Ontology?

• A formal explicit description of concepts in a domain of discourse (aka classes or concepts)

• properties of each concept that describe features or attributes of the concept (aka slots)

• relations between concepts• restrictions of these attributes

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Ontology Hierarchy• Main focus: classes• Classes describe concepts in a domain• Ex: class Dog represents all dogs• Subclasses -> labrador, terrier, collies, etc• slots -> size, weight, color, furLength…• Instances -> Penny

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Database Schema vs. Ontology

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Database Schema Ontology

What’s it for? Data storage and retrieval

Conceptualization, meaning

Who uses it? Databases Humans, software

Meaningful without instances?

No Yes

Ontology DevelopmentFundamental Rules:

1. There is no one correct way to model a domain. The best solution almost always depends on the application and extensions you have in mind.

2. Ontology development is necessarily an iterative process.

3. Concepts in the ontology should be realistic to objects and relationships in the domain.

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Ontology Development

• Step 1: Determine Domain and Scope

• Step 2: Consider reusing existing ontologies

• Step 3: Enumerate important terms

• Step 4: Define classes and class hierarchy

• Step 5: Define properties of classes (slots)

• Step 6: Define constraints of slots

• Step 7: Create instances

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Why Develop an Ontology?

• To share common understanding of the

structure of information among people

• To enable reuse of domain knowledge

• To make domain assumptions explicit

(especially in software or databases)

• To analyze domain knowledge

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Example

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Applications and Research● Sharing domain knowledge across institutions

○ E.g., biology and biomedical research

● Data integration○ E.g., merging databases

● Semantic Web○ Syntax vs. semantics

● Ontology Languages○ RDF, OWL, SPARQL, others

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Biology and Biomedical Research● Gene Ontology● Foundational Model of Anatomy

○ Representation of human body understandable by humans and computers

○ Explore

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References

• https://www.researchgate.net/profile/Jake_Cobb/publication/236842047/figure/fig1/AS:2

99445456523267@1448404768571/Figure-1-Example-pizza-ontology-represented-as-a-gra

ph-G-a-and-a-changed-version-of.png

• https://protege.stanford.edu/publications/ontology_development/ontology101-noy-mcgui

nness.html

• http://hollergen677s09.weebly.com/protein-network.html

• https://www.slideshare.net/UscholdM/ontologies-and-db-schema-whats-the-difference

• https://link.springer.com/book/10.1007%2F978-3-540-92673-3

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Sandwich Ontology

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