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

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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/