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A Controlled Natural Language Interface for Semantic MediaWiki
Jie BaoRensselaer Polytechnic Institute
Paul R. Smart, Nigel R. ShadboltUniversity of Southampton
Dave Braines, Gareth JonesIBM UK
ACITA 2009, Sep 23, 2009 University of Maryland
Motivation
“The timely collection of facts obtained at the tactical (and even the interpersonal level) may help to create better operational decisions at all levels. The goal is to create networks of soldiers who are capable of collecting information within their sphere of influence and who can share this information with other members of the net in a timely fashion.”
---Defense Science Board. 2006 Summer Study on 21st Century Strategic Technology Vectors, Volume II, Critical Capabilities and Enabling Technologies. Office of the Under Secretary of Defense for Acquisition, Technology, and Logistics, Washington, DC, 2006.
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Motivation
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Shared Repository
Multinational Planning Teams
Military Platforms
Unmanned Vehicles
Analysts
Intelligent Agents/Assistants
Patrols / Field Reports
Non- MilitaryOrganizations
RemoteSensors
Key Requirements
• Collaboration Support– Can be used by a variety of different types of contributors – Supports cross-platform access
• Ease of Use– Requires least training– Provides simple user interface– Content ease to understand
• “Meaningful” Structure– Enables some automated processing of data (e.g., automated
data propagation)– Enables discovery of “hidden” knowledge from explicitly known
information.
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Enabling Technologies
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Semantic Wiki
ControlledNatural
Language
Every A is B …+
Semantic Wiki
Semantic Wiki
Multi-user content creation and editing
Browser-based, Cross-platformeasy to use
Support semantic annotations for automated processing and inference
Semantic MediaWiki (SMW)
• It is the most popular semantic wiki system extending MediaWiki (the Wikipedia’s platform)
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Mediawiki: What you edit what you see
Semantic MediaWiki
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SMW: What you edit(Modeling Script)
what you see
typed link (property)
To author knowledge
Semantic MediaWiki
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SMW: What you edit(Querying Script)
what you see
To retrieve knowledge
Challenges
However, SMW is limited by Expressivity constraints
• No support for the full range of RDF/OWL• E.g., we can’t specify that “capital of” property should always link
a City to a Country (property domain and range)
Usability• Thinking in the “subject-property-object” fashion may not be
ease (as one may think!)• Based on our own experiments with entry-level users.
• Knowledge engineers may find it difficult to understand other’s contributions.
• Users may prefer different languages styles or even different natural languages.
Challenges
However, SMW is limited by Expressivity constraints
• No support for the full range of RDF/OWL• E.g., we can’t specify that “capital of” property should always link
a City to a Country (property domain and range)
Usability• Thinking in the “subject-property-object” fashion may not be
ease (as you may think!)• Based on our own experiments with entry-level users.
• Knowledge engineers may find it difficult to understand other’s contributions.
• Users may prefer different languages styles or even different natural languages.
By extending SMW with an OWL Meta-model
(introduced in details later)
By allowing modeling/representing knowledge using controlled natural language (CNL)
Controlled Natural Language
CNL
Every A is B…
Production of knowledge without using a formal logic.
Potential production and comprehension benefits
Multiple OWL-compliant CNLs are available:e.g. Rabbit, Sydney OWL Syntax, ACE-OWL
Controlled Natural Language
Example (In Rabbit syntax):• The “capital of" relationship can only have a “City" as a
subject.• The "capital of" relationship can only have a “Country"
as an object.
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Instead of saying (In OWL Abstract Syntax)
ObjectProperty(ex:capital_ofdomain(ex:City) range(ex:Country))
Or (In Description Logics)
∀capital_of.T ⊆City ∀capital_of -.T ⊆ Country
Solution Summary
• Collaboration Support– Natively collaborative for a wiki– Web-based interface accessible from any device that has a
browser.
• Ease of Use– Simplify knowledge input using semi-automatically generated
forms– Multiple OWL-compliant CNLs: e.g. Rabbit (English, Chinese),
ACE-OWL
• “Meaningful” Structure– Meta-model do the translation between OWL and CNL, and
between OWL and SMW scripts– Query and inference supported.
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Architecture
Wiki Database
Form Editor Interface CNL Interface CNL Editing
InterfaceRDF Export
Interface
RDF Model
RDF Import Semantic Query Interface
RDF Export
CNLGModule
SELECT ?xWHERE{
?x rdf:typeowl:Class}
Prototype system: http://tw.rpi.edu/proj/cnl
Class(Rabbit partial intersectionOf(animalrestriction(eat someValuesFrom(FreshVegetable)))
OWL: “Rabbit eats some fresh vegetable”
SMW OWL Meta Model
Us wiki templates to create OWL meta-model extensions for SMW
Form-based editing interface associated with templates
1
3 2
OWL Class Templates
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Similarly, we have templates for properties and individuals
CNL Generation
{{#vardefine:label|{{CNL.getLabel|{{{1}}} }} }} {{#vardefine:super |
{{#ask: [[:{{{1|{{FULLPAGENAME}}}}}]] |?Category= |mainlabel=-|format=list|link=none }}
}}
{{#if: {{#var:super}} |{{#arraymap:{{#var:super}}|,|xxx|<li>Every[[:{{{1}}}{{!}}{{#var:label}}]] is a kind of
[[:xxx|{{CNL.getLabel|xxx}}]] }}|}}
Use SMW queries to retrieve knowledge statements in the OWL meta model
Construct sentences according to the syntax of the target CNL
Multiple CNL Support
Accommodating new CNLs requires relatively minor changes to the wiki script
I/O Support
• Allows importing of an RDF/OWL ontology• Exporting in three CNL syntaxes• Ontology in the meta-model can be exported in
RDF.
• Some limitations apply– Limitation supports for blank nodes– Datatypes– Ontology management (e.g. imports)
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Related work
AceWikiDifferences:• underlying wiki system• editing interface• light-weight extensions• support for multiple CNLs• customization of target
CNLs
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Tobias Kuhn (2008)
Related work
ROO
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Vania Dimitrova et al. 2008
Differences:• Protégé-based vs. wiki-
based• Rabbit only vs. multiple
CNLs• Formal modeling only vs.
formal+informal modeling
Summary
• We have developed an OWL meta-model extension to SMW to support the representation of OWL ontologies
• We have provided a light-weight form-based interface to support ontology editing
• We have provided an RDF import mechanism to support the import of existing ontologies
• We have developed multiple CNL ‘verbalizers’ to support the serialization of semantic wiki content to CNLs
• Future work:– Improved expressvity– Enable users to create/customize CNL output– Implement wiki-based CNL editing capability
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http://tw.rpi.edu/proj/cnl/