ONTOLOGIES Presentation for e-business systems development BN3374 Tom Raby
Jun 15, 2015
ONTOLOGIESPresentation for e-business
systems development BN3374Tom Raby
What is an Ontology?
Definition:
“ Ontologies are ways of organising and describing related items, and are used to represent semantics.”
“ Ontology involves discovering categories and fitting objects into them in ways that makes sense.”
Example
Components
Classes – Collections, concepts Individuals – Instances or objects. The basic
objects Attributes – aspects, properties, features Values / Properties – Individual related specific
data. Value of the properties / attributes Relations – ways in which individuals/classes
relate to one another Events – the changing of attributes or relations
Components
Classes – Collections, concepts
Example
Components
Classes – Collections, concepts Individuals – Instances or objects. The
basic objects
Example
Components
Classes – Collections, concepts Individuals – Instances or objects. The basic
objects Attributes – aspects, properties, features
Example
Components
Classes – Collections, concepts Individuals – Instances or objects. The basic
objects Attributes – aspects, properties, features Values / Properties – Individual related
specific data. Value of the properties / attributes
Example
Components
Classes – Collections, concepts Individuals – Instances or objects. The basic
objects Attributes – aspects, properties, features Values / Properties – Individual related specific
data. Value of the properties / attributes Relations – ways in which individuals/classes
relate to one another
Example
Components
Classes – Collections, concepts Individuals – Instances or objects. The basic
objects Attributes – aspects, properties, features Values / Properties – Individual related specific
data. Value of the properties / attributes Relations – ways in which individuals/classes
relate to one another Events – the changing of attributes or relations
Example
What makes a good Ontology?
Syntax Identified with form, format and structure of the data. Programs such as RDF (research development framework) OWL
(ontology web framework) SQL and Java all improve the form and format of the ontology
Structure Databases, semantic web and ontologies require good structure to
organise and contain elements of the model. Semantics
Semantic interpretation is the mapping between some structured subset of data and the set of objects with respect to the intended meaning of those objects and the relationships.
Pragmatics Intent of the semantics and actual semantic usage. There is very
little pragmatics expressed or even expressible in programming or database languages, but will become important.
The need for Ontologies
With increasing levels of data, the need to categorise it and develop a framework and understanding of it increases.
Allows greater level of integration. Able to express the semantics of your data,
document collections, and systems using the same semantic resource that is machine interpretable.
Re-use previously developed versions, bring in different or related ontologies, and extend the ontology. This helps to establish community wide common semantics.
Closing Comments
Ontologies are used to improve the structure and data used in a web page
Categorise s and develops data into a structure that makes sense.
Complicated but becoming essential to generate full use of data
Needs to be machine interpretable. Machines cannot make assumptions like humans
QUESTIONS?
References
Deitel, P.J. Deitel, H.M. (2008). Internet &World Wide Web How to Program. 4th ed. New Jersey: Pearson Education Inc. 96.
Daconta, M. Obrst, L. Smith, K (2003). The Semantic Web. A Guide to the eFuture of XML, Web services, and Knowledge Management. Indianapolis: Wiley Publishing Inc. 181-238