European Schoolnet David Massart [email protected] Tel Aviv University - Jan. 16, 2005

European Schoolnet

David Massart <[email protected]> Tel Aviv University - Jan. 16, 2005.

European Schoolnet

Outline

• Context, motivations, and requirements

• The SQI Application Programming Interface

• Usage scenarios

• Current status

• Bindings and Application Profiles

• Who is using it ?

• The Celebrate Gateway

• The iClass Adapter

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Query Service Interoperability

In order to be able to query each others, repositories must agree on:•A Query Language

•A Result Format

•A Query Interface

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SQI is an Application Program Interface (API)

• An API for querying learning objects repositories

• Since one major design objective is to keep the specification simple and easy to implement, the interface is labelled Simple Query Interface (SQI)

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Who Is Behind It ?

• API Specification:– CEN/ISSS Learning Technology Workshop– E. Duval, D. Massart, B. Simon, S. Ternier, F.

Van Assche, M. Arnaud

• Implementations:– WP3 ProLearn network of Excellence (FP6)– Ariadne, Celebrate, Edutella, Elena, ...

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Motivations

Small-step approach:

• Connecting as many European LO repositories (metadata search) as possible

• Proving that it works

• Creating the need for better interoperability

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Requirements

Combining highly heterogeneous repositories requires to:

• Be neutral in terms of results format and query languages

• Support Synchronous and Asynchronous Queries in order to allow heterogeneous networks to connect to each other

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Result Schema Neutrality ?

• Any schema that two or more repositories have agreed on is valid

• An SQI schema serves two purposes:– It identifies the set of attributes and vocabularies

that can be used in the query– It provides a format in which learning object

descriptions are returned– For example, both XML schemas and RDF

schemas are valid

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Query Language Neutrality

• Query languages– are not neutral– Any query language chosen (e.g. XQUERY)

would have a negative impact on the adoption of the interface by those repository types the language has not been designed for (e.g. RDF repositories in the case of XQUERY).

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Why Neutrality ?

SQI

• Does not contribute to overcome the differences of the various paradigms in metadata management (Z39.50, XML-based approaches, RDF community)

• Aims at becoming an independent specification for all open educational repositories

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Why Asynchronous ?

FederationHost 1

FederationHost 2

FederationHost 3

SQIGateway

SQI

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Why Asynchronous ?

FederationHost 1

FederationHost 2

FederationHost 3

SQIGateway

SQI

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Asynchronicity

• Simple

• Robust

• Scales up well

• Enables Selective Dissemination of Information (SDI)

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What is SQI good for ?

• Metadata search of LO repositories

• Any search (metadata, full text, ...)

• Any “function” (e.g., in the iClass project, SQI is also used to obtain LOs)

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The SQI Application Program Interface

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SQI Methods• Query Configuration

– setQueryLanguage

– setResultsFormat

– setMaxQueryResults

– setMaxDuration

• Synchronous Query Interface– setResultsSetSize

– synchronousQuery

– getTotalResultsCount

– getAdditionalQueryResults

• Asynchronous Query Interface– asynchronousQuery– setSourceLocation– queryResultsListener

• Session Management– createSession– createAnonymousSession– destroySession

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Fault Mechanism

• Intentionally unsophisticated

• Simplicity rather than richness

• Only one fault: SQIFault– Thrown by all methods– Allows:

• Free-text messages

• Predefined error codes

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A Simple Scenario

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Getting Additional Results

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Asynchronous Query Mode

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Federated Search Front End

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Current Status

IT IS HAPPENING NOW !• Version 1.0 alpha was realeased in Dec. 2004• Call for comments ended last week• Comments will be reviewed this week in

Vienna• CEN/ISSS LTWS meeting in Oslo next week

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SQI Users

Who is using it ?

• The ProLearn network of excellence (FP6)

• The iClass project (FP6)

Who will use it ?

• IMS Global SIG “Query Service”

• You:– EUN LIFE (workshop + plugfest)– iClass

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Bindings and Application Profiles

Bindings:

• Common SQI WSDL

• Java Exception Hierarchy

Application Profiles:

• Celebrate / Ariadne (LOM/VSQL)

• Elena / Edutella (RDF)

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The Celebrate Gateway

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CeLeBraTe(Context eLearning with Broadband Technologies)

• 30 months / € 7 M. project (=>Nov. 2004)

• Was supported by the European Commission's IST Program (FP5)

• Involved 500 schools across Europe

• 22 partners (European ministries of education, universities, leading educational publishers and technology suppliers)

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Celebrate's Goals

Consist in creating:

• New contents (LOs)

• An innovative pedagogy (based on LOs)

• A European learning network (to exchange LOs)

• A new business model (Merlin)

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Brokerage of Networks

ARIADNE ELENA

CELEBRATEFederation

..

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Federated Search

MessagingMessagingServerServer

EUNEUNLMS/LCMSLMS/LCMS

ELN ClientELN Client

Brok. SystemBrok. SystemCentral serv.Central serv.


DigitalbrainDigitalbrainLMS/LCMSLMS/LCMS


GiuntiGiuntiLMS/LCMSLMS/LCMS


Sanoma Sanoma WSOYWSOY LMS/LCMSLMS/LCMS


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Federated Search












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Federated Search























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Federated Search























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Federated Search























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SQISQI SQISQI

SQISQI

SQISQI

SQISQI

SQI Gateway

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Brokerage of Networks

ARIADNE ELENA

..

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Architecture

Gateway

Translation

Core

Admin

SQI

Connection

Configuration

fileELN

Client

Brokerage System

SQISQI

SQISQI

SQISQI

SQISQIadministrator

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ImplementationTranslation package

Querytranslatio

n

CELEBRATEFilter

(xml instance)

VSQL(xml

instance)

Resultstranslatio

n

CELEBRATEResultset

(xml instance)

IEEE LOMResultset

(xml instance)

Using: - XSLT ( the Extensible Stylesheet Language Transformations)- JAXB (Java Architecture for XML Binding) - JAXP (Java API for XML Processing)

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The Celebrate Gateway

• Supports:– Very Simple Query Language (VSQL)– Simple School Query Language (S2QL)– Strict LOM

• Accepts queries in asynchronous mode

• Propagates both synchronous and asynchronous queries

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The iClass Adapter

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iClass

• Develops an Intelligent distributed Cognitive-based Learning System for Schools

• Funded under the FP6

• Initiated in January 1, 2004

• 22 partners from 11 countries

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iClass Adapter

• Enables the end-users of “legacy systems” to search and access iClass Learning Objects

• Is based on SQI

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Components

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Sequence Diagram

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SQI

http://www.prolearn-project.org/lori

http://sqi-wsdl.sourceforge.net/

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Documents

European Schoolnet David Massart [email protected] Tel Aviv University - Jan. 16, 2005