Post on 22-Feb-2016
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MGED Ontology [--usage]
MGED Ontology Working GroupDec, 2003
Outline• Brief overview of MGED Ontology (MO)
– Structure of MO– What is in MO– Uses of MO– MAGE and MO
• MGED Ontology use policies– Simple examples– Nested term examples– Referencing outside terms with MO
Ontologies in general• Explicit specification of a conceptualization
– Defines a vocabulary with which queries and assertions are made• Classes - base type
– Animal, Cat, Dog– BioMaterial, Age, TechnologyType– IS-A relationships: Cat IS-A Animal
• Properties - attributes of classes– number_of_legs, natural_enemy– HAS-A relationships: Cat HAS 4 legs
• Individuals - instantiations of classes– calico, hound, “Stinky Pete”
• Axioms - logic statements– Cat != Dog
MGED Ontology (MO)• Core ontology limited
to MAGE-OM v.1.1• Extended Ontology
augments the Core with terms currently outside the scope of MAGE v.1.1
OilEd editor: http://oiled.man.ac.uk/ Protogé: do google search for it
MAGE and MO
MAGE and MO
Main focus of MGED Ontology• Structured and rich
description of BioMaterials
BioMaterial
OntologyEntry
+characteristics
+associations
A graph representation
MGED Ontology Announcements
• http://www.mged.sf.net/ontologies– About to release first stable release of the Core ontology
(version 1.1.7)– Provide usage of the ontology and examples– Lot’s of links to ontology resources on the web
• Policies – Any term not referenced via DatabaseEntry is by default
user-defined and not part of MO• ‘accession’ and ‘URI’ are not both needed• Refers to OntologyEntry.value
– MO terms may be used in “category” for other ontology’s term (e.g. “Organism”)
Referencing MO Terms<MAGE-ML> …<Database name="The MGED Ontology" identifier="MO"
URI="http://mged.sourceforge.net/ontologies/MGEDontology.php" />…<OntologyEntry category="SomeMOClass" value= "some_MO_instance"> <OntologyReference_assn> <DatabaseEntry accession="#some_MO_instance" URI="http://mged.sourceforge.net/ontologies/MGEDontology.php#some_MO_instance"> <Database_assnref>
<Database_ref identifier="MO"/> </Database_assnref> </DatabaseEntry> </OntologyReference_assn></OntologyEntry>…</MAGE-ML>
Graph representation of previous slide’s XML
Individuals
• Instance term goes into value and is the referenced term.
• Parent term goes into category
Classes with Properties• Nested structure via OntologyEntry.Association• Fillers:
– base types (boolean, string, etc.)– Classes/Instances– Enumeration of Instances
• OntologyEntry category & value = Property• Filler is given as OntologyEntry Association
– follow the rules– When a base type, OntologyEntry.category = Property
Measurement Example
Enumeration of instances Base type Class/Instance
Enumerated instances example
Base type example
Class/Property example
This is BAD! An example of node skipping or tree collapsing
Including parent classes
• You may include parent classes for ease of queries, but you must reproduce all of the structure from the parent to the term of interest
Here we have included the parent term “Action” to the instance term “add” and have included the full term tree.
“Abstract” classes• These are classes without individuals
– Usually have “user-defined” instance terms• Term goes in OntologyEntry “category” and
“value” attributes and referenced via DatabaseEntry
• User-defined term is “Association” (or child OntologyEntry term) with abstract class in category and new term in value, unreferenced
• Example: Your BioMaterial source had a Disease “foobar”
Referencing terms in other ontologies
• Special case of last slide, were new term optionally references some other ontology via its DatabaseEntry
• In addition, specify from within the MGED Ontology where the term hailed from– Is-a “OntologyEntry” term has properties:
• has_database = source for the term• accesion = accession for the term in• value = the term from the source
Without extra DatabaseEntry
With DatabaseEntry
Thanks
• MGED Ontology Working Group