A Visual Approach to Semantic Query Design Using a Web-Based Graphical Query Designer

Paul R. Smart, Alistair Russell, Dave Braines, Yannis Kalfoglou, , Jie Bao and Nigel R. Shadbolt

Presented by Kristine MonteithCS 652 – Information Extraction and Integration

5/21/09

Overview

• Semantic Query Languages such as SPARQL are important tools for Information Retrieval

• This paper presents a tool to aid in the process of query formation

• Visual Query Systems • Syntactically valid queries• Avoid lexical and syntactic errors• Possibility of improved efficiency, understanding,

and reduced training requirements

vSPARQL Visual Query Language

• Set of graphic notations that support the visual representation of SPARQL query components

• Outline• Core SPARQL Features• Triple Patterns • Simple Select Query• Graph Patterns • Solution Sequence Ordering • SPARQL CONSTRUCT Queries• Other SPARQL Features

Core SPARQL Features

Triple Patterns

Simple Select Query

PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>PREFIX edto: <http://www.e-defence.org/ontologies/terrorism.owl#>

SELECT ?activity ?dateWHERE{

?activity rdf:type edto:Activity.?activity edto:hasDate ?date

}

Simple Select Query

Graph Patterns • Each variable has local scope with respect to the graph pattern in

which it is contained

PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>PREFIX edto: <http://www.e-defence.org/ontologies/terrorism.owl#>

SELECT ?activityWHERE{

{?activity rdf:type edto:MilitaryActivity}.{?activity rdf:ytpe edto:BiologicalActivity}

}

Graph Patterns

Other Graph Patterns

• Optional graph patterns• Union graph patterns• Allow users to specify alternatives for graph

pattern matching

Solution Sequence Ordering

• Specify the order in which query results are returned

Filtering

PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>PREFIX edto: <http://www.e-defence.org/ontologies/terrorism.owl#>

SELECT ?activity ?activityDateWHERE{

?activity rdf:type edto:Activity?activity edto:hasDate ?activityDateFILTER (?activity>"2005-01-01T00:00:00Z"^^xsd:dateTime)

}

Filtering

SPARQL CONSTRUCT Queries • Define both a set of triples to match against the rdf graph and a template

for rdf construction

CONSTRUCT{

_:a rdf:type edto:TerroristAttack._:a edto:hasICN ?aaip_ICN.?x owl:sameAs _:a

}WHERE{

?x rdf:type aaip:TerroristIncident?x aaip:hasICN ?aaip_ICN?y rdf:type edto:TerroristAttack?y edto:hasICN ?edto_ICN

}

SPARQL CONSTRUCT Queries

Other SPARQL Features

• Supported in the NITELIGHT tool• Not part of the vSPARQL specification• ASK and DESCRIBE query forms• DISTINCT, LIMIT and OFFSET solution modifiers

NITELIGHT Tool

Additional Application Areas

• Rule Creation • Take advantage of multiple knowledge bases

• Information Integration and Interoperability• Ontology alignments between ostensibly disparate

ontologies

Rule Creation

CONSTRUCT {

?z edto:hasSuspectedResponsibilityFor ?x } WHERE{

?x rdf:type edto:TerroristAttack . ?x edto:isPerformedBy ?y . ?y edto:isMemberOf ?z . ?z rdf:type edto:TerroristOrganization

}

Information Integration and Interoperability

PREFIX edto: <http://www.e-defence.org/ontologies/terrorism.owl#> PREFIX ito: <http://www.ito.org/terrorism.owl#> PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#> PREFIX owl: <http://www.w3.org/2002/07/owl#> PREFIX xsd: <http://www.w3.org/2001/XMLSchema#>

CONSTRUCT {

_:t rdf:type edto:TerroristAttack . _:t edto:isSuicideAttack xsd:true . _:d ref:type edto:ExplosiveDevice . _:t edto:uses edto _:d

} WHERE {

?x rdf:type ito:TerroristIncident . ?x ito:hasType ito:Bombing . ?x ito:involvesWeapon ito:Explosive . ?x ito:hasVictim ?victim . ?victim ito:isFatality xsd:true . ?victim rdf:type ito:Terrorist . ?x ito:perpetratedBy ?victim

}

Strengths

• Helped me understand SPARQL better• Enforces correct syntax• Seems like an attractive, easy-to-use program

Weakness

• Requires the user to already be familiar with SPARQL

• Tool not available online• Ontology not available online

Future Work

• User evaluation study already planned

QUESTIONS?