NESSTAR: A Semantic Web Application for Statistical Data and Metadata

n NESSTAR: A Semantic Web Application for

Statistical Data and Metadata

Pasqualino “Titto” AssiniPasqualino “Titto” AssiniNesstar Ltd - UKNesstar Ltd - UK

Nesstar - Networked Social Science Tools and Resources

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• NESSTAR: NEtworked Social Science Tools And Resources (a.k.a. the “Data Web”)– What is all about? The domain: statistical

information.– What is the “Data Web”?– End User and Data Publisher Views– Requirements

• The Underlying Architecture: NEsstar Object Oriented Middleware (NEOOM)– Web Oriented: based on Semantic Web technology– Object Oriented – Domain Independent

• Implementation

• Design and Development Process

Contents


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• The Domain: Surveys, Opinion Polls, Censuses

• The Actors: – Data Publishers: Social Sciences Data Archives, Statistical

Offices, Private Research Institutes (Gallup, etc)– Data Users: Social Researchers, Journalists, Marketing

Experts

• The Problem– Simplify publishing, finding and accessing statistical

information.

The Domain and the Problem


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• The Web is a very successful example of a distributed information dissemination system

• Can we learn something from the Web?

• Idea: Use (Semantic) Web principles and technologies to create a “Data Web”

Learning From the Web


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What is the Data Web?What is the Data Web?

• The Data Web is the application of Semantic

Web techniques and principles to the

problem of distributed data dissemination

and processing.


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User view: Data Web BrowserUser view: Data Web Browser

LOCATION BAR

OBJECTBROWSER

BOOKMARKS

OPERATION

OPERATION RESULTBROWSING


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Publisher View: Object Model Publisher View: Object Model

PROPERTIES

RELATIONSHIPS

TYPE

METHODS

INHERITANCE


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RequirementsRequirements

• Support for the Object Model:– An interface definition language that supports

Types, Properties, Relationships and Methods RDF Schema (no Methods)

• Distributed object model extensibility: – Inheritance RDF

• Integration with the Web:– Objects, Types and method invocations have a URL – Object state is accessible via HTTP Objects (and

types) self-describe themselves in RDF– Method invocations can be performed via HTTP

SOAP, HTML FORM


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• Semantic Web (RDF/RDF Schema) plus:

– Self-description principle: objects and types self-describe themselves by making accessible their RDF description at their URL (dynamic discovery)

– RDF Schema Model for Methods

– Method Invocation Protocol based on HTML FORM

Nesstar Object Oriented Middleware


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Method ModelMethod Model


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• Method Invocations are:

– Performed as HTML FORM methods

Very easy to generate forms that correspond to method invocations

– Coded as normal URLs:• Ex:

http://15.245.54.37/obj/Server?..method=Login&userID=admin&userPassword=mypwd

Method Invocation Protocol


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Web closely integrated with the (Semantic) Web.

• Advantages:– Support for sophisticated Object

Oriented Models– Distributed Extensibility– Integration with the (Semantic) Web– Compatibility With Existing

Languages/Protocols/Applications– Programming Language Independence

What Have We Got?


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System ComponentsSystem Components


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Design/Development Use CasesDesign/Development Use Cases


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Presentation Layer IndependencePresentation Layer Independence


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Web Links to Statistical ObjectsWeb Links to Statistical Objects

This is a Nesstar Server object …

Get linked objects


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Web Links to Statistical OperationsWeb Links to Statistical Operations

Demo

• Object Browser (new EJB Server)

• Data Archive Server

http://nesstar2.essex.ac.uk/browser?FRAMES=true&url=http://nesstar2.essex.ac.uk/neoomtest/servlet/NEOOM2EJB/obj/cServer/ESSEXTEST

http://nesstar.data-archive.ac.uk/index.jsp

Documents

NESSTAR: A Semantic Web Application for Statistical Data and Metadata