An Introduction to

Ontological Modeling

Laura Baker, Amanda Goodman, Martha Parker LIS 688 Metadata

“When we enter metadata we can focus on exactly what we know and not have to try to anticipate every way

someone might want to use the metadata.”-- Brian Lowe

What is Ontology?

A “vocabulary of interrelated terms

which impose a structure for the domain

and constrain the possible interpretation terms.” (Kalinichenko, 2003)

What is a Domain?

An area of study or a subject area.

Ontologies Include…

• Controlled Vocabularies• Thesauri• Classification Schemes• Taxonomies

• Topic maps• Frame language• Logical theories

Four Classes

• Verbal• Logic-based• Structural (object)• Hybrid

Different models are used by different communities.

Ontologies Express Relationships

Temporal. Positional. Causal.

Background

• Keyword searches are popular but lack precision.• Metadata terms are disregarded thanks to spammers.• Ontology enrich simple search strategies by defining relationships.

Literature Review

Ontologies can be Misrepresentative

• What is left out is as important as what is included.• The relationships represented “provides a particular perspective on the world” (Brewster & O’Hara, 2007).

• Errors can spread from one ontology to another if combined.• Ontologies are a surrogate for real world objects and relationships.

The Umbrella of Knowledge Management

• Legacy management of knowledge• Different formats• One concept, many names• Types of knowledge

Related Areas

• Information sharing• Semantic web• Individual knowledge• Hierarchical knowledge• Knowledge objects

Knowledge Lens

• Simplifies ontology • Focuses on the essential

The Importance of Being Contextual

What device is being used to access the information?

Ontology Management Systems

• The SnoBase system manages ontologies in database tables.• Can be searched with simple SQL queries.• Does not require new equipment

Specific Application

CIDOC Conceptual Reference Model

CRM History

• Developed by the CIDOC Documentations Standards Working Group and CIDOC CRM SIG • Created relational data model for museums• In 1996 focus changed to an object-oriented approach• First CRM completed in 1999

Object Association Information Element Relationships

• For-actual instance of use• General use-activity type• Made for-event • Intended for-activity type

CRM Constraints: An Example

Constraints are intended to maintain a level of focus so that theontology doesn’t expand indefinitely.

Cultural Heritage Collections

“All types of materials collected and displayed by museums and Related institutions as defined by the International Council ofMuseums.” (CIDOC, 2006).

Final Thoughts

Positives: •Relationships between defined vocabularies•Potential to improve precision for query results

Negatives:•No established evaluation techniques•Not many digital libraries are semantic•Lack of resources and knowledge

Image CreditsImage Credits

• http://www.flickr.com/photos/melodysk/499419404/• http://www.flickr.com/photos/melodysk/499473826/in/photostream/• http://ecommons.cornell.edu/bitstream/1813/5370/1 /ontologies.MWG.20070216.ppt• http://www.flickr.com/photos/jrguillaumin/3419172904/• http://www.flickr.com/photos/stolidsoul/433082097/• http://www.flickr.com/photos/ken_from_md/4969123149/• http://www.flickr.com/photos/navdeepraj/504596529/• http://www.flickr.com/photos/franklin_hunting/2954700555/• http://www.flickr.com/photos/jim-sf/3391348814/• http://www.flickr.com/photos/julietteculver/4615763263/• http://www.flickr.com/photos/wwworks/4632864373/• http://www.flickr.com/photos/chelseafarmersmarket/4572046793/• http://www.flickr.com/photos/johnfahertyphotography/2675723448/• http://www.flickr.com/photos/essjay/4361793502• http://www.flickr.com/photos/fenoswin/5654091521/