On 09/07/13 05:12, Erdem Eser Ekinci wrote:
Hi all,
I need some help to validate an ontology. The code is as follows. The
ontology is simple; there are tree concepts; Role, Goal, Task and one
object property hasGoal whose domain is Role and range is Goal. I've tried
to restrict Role concept on the hasGoal property with allvalues, somevalues
and mincardinality restrictions separately. But none of them hampers the
validity. Always validation true.
What am I missing?
That OWL with the standard open world semantics is fundamentally
unsuited to validation :)
It is possible to use OWL syntax to express constraints but interpret it
with closed world semantics. See upcoming W3C workshop on this topic.
But the current jena rule reasoners follow the official semantics.
In your example then a cardinality restriction on Role just means that
each Role instance can be deduced to have a hasGoal, and indeed the
reasoner will invent an existential variable (blank node) to represent
the missing value.
Similarly a someValues restriction just means that the reasoner can
deduce there is a hasGoal value and that it must be a Goal.
An allValues restriction allows you to deduce that all your hasGoal
values must be Goals but tells you nothing about missing goals. If you
made the value of a hasGoal instance a Task, and if you declare Task and
Goal to be disjoint then your allValues (or a simple range declaration)
would allow you to detect a problem.
Dave
Thanks for your help...
public class OWLRestrictionTest {
//uri defs
private static String URI_BASE = "
http://www.galaksiya.com/ontologies/galaxia.owl";;
private static String URI_INDV = "
http://www.galaksiya.com/ontologies/indv.owl";;
private static String URI_ROLE = "Role";
private static String URI_GOAL = "Goal";
private static String URI_TASK = "Task";
private static String URI_HAS_GOAL = "hasGoal";
// concepts
private OntClass clssRole;
private OntClass clssGoal;
private OntClass clssTask;
private ObjectProperty prpHasGoal;
@Test
public void test() {
OntModel schema =
ModelFactory.createOntologyModel(OntModelSpec.OWL_DL_MEM_RULE_INF);
//create concepts
clssRole = schema.createClass(URI_BASE + "#" + URI_ROLE);
clssGoal = schema.createClass(URI_BASE + "#" + URI_GOAL);
clssTask = schema.createClass(URI_BASE + "#" + URI_TASK);
//create properties
prpHasGoal = schema.createObjectProperty(URI_BASE + "#" + URI_HAS_GOAL);
//create restrictions
//Restriction restriction = schema.createSomeValuesFromRestriction(null,
prpHasGoal, clssGoal);
Restriction restriction =
schema.createAllValuesFromRestriction(null, prpHasGoal, clssGoal);
//Restriction restriction = schema.createMinCardinalityRestriction(null,
prpHasGoal, 2);
clssRole.addSuperClass(restriction);
OntModel data = ModelFactory.createOntologyModel();
//create individuals
Individual indvRole1 = data.createIndividual(URI_INDV+"#FetcherRole1",
clssRole);
Individual indvGoal1 = data.createIndividual(URI_INDV+"#FetchGoal1",
clssGoal);
Individual indvTask1 = data.createIndividual(URI_INDV+"#FetchTask1",
clssTask);
//indvRole1.addProperty(prpHasGoal, indvGoal1);
indvRole1.addProperty(prpHasGoal, indvTask1);
//validation
schema.write(System.out,"N3");
ValidityReport validityReport = schema.validate();
if(validityReport != null)
System.out.println("Model consistency: " + validityReport.isValid());
else
System.out.println("No consistency report");
Reasoner reasoner = ReasonerRegistry.getOWLReasoner();
reasoner.bindSchema(schema);
InfModel infModel = ModelFactory.createInfModel(reasoner, data);
infModel.write(System.out,"N3");
ValidityReport validityReport1 = infModel.validate();
if(validityReport1 != null)
System.out.println("Model consistency: " + validityReport1.isValid());
else
System.out.println("No consistency report");
}
