european schoolnet david massart [email protected] tel aviv university - jan. 16, 2005
TRANSCRIPT
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.
ELN ClientELN Client
DigitalbrainDigitalbrainLMS/LCMSLMS/LCMS
ELN ClientELN Client
GiuntiGiuntiLMS/LCMSLMS/LCMS
ELN ClientELN Client
Sanoma Sanoma WSOYWSOY LMS/LCMSLMS/LCMS
ELN ClientELN Client
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Federated Search
MessagingMessagingServerServer
EUNEUNLMS/LCMSLMS/LCMS
ELN ClientELN Client
Brok. SystemBrok. SystemCentral serv.Central serv.
ELN ClientELN Client
DigitalbrainDigitalbrainLMS/LCMSLMS/LCMS
ELN ClientELN Client
GiuntiGiuntiLMS/LCMSLMS/LCMS
ELN ClientELN Client
Sanoma Sanoma WSOYWSOY LMS/LCMSLMS/LCMS
ELN ClientELN Client
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Federated Search
MessagingMessagingServerServer
EUNEUNLMS/LCMSLMS/LCMS
ELN ClientELN Client
Brok. SystemBrok. SystemCentral serv.Central serv.
ELN ClientELN Client
DigitalbrainDigitalbrainLMS/LCMSLMS/LCMS
ELN ClientELN Client
GiuntiGiuntiLMS/LCMSLMS/LCMS
ELN ClientELN Client
Sanoma Sanoma WSOYWSOY LMS/LCMSLMS/LCMS
ELN ClientELN Client
MessagingMessagingServerServer
EUNEUNLMS/LCMSLMS/LCMS
ELN ClientELN Client
Brok. SystemBrok. SystemCentral serv.Central serv.
ELN ClientELN Client
DigitalbrainDigitalbrainLMS/LCMSLMS/LCMS
ELN ClientELN Client
GiuntiGiuntiLMS/LCMSLMS/LCMS
ELN ClientELN Client
Sanoma Sanoma WSOYWSOY LMS/LCMSLMS/LCMS
ELN ClientELN Client
European Schoolnet
Federated Search
MessagingMessagingServerServer
EUNEUNLMS/LCMSLMS/LCMS
ELN ClientELN Client
Brok. SystemBrok. SystemCentral serv.Central serv.
ELN ClientELN Client
DigitalbrainDigitalbrainLMS/LCMSLMS/LCMS
ELN ClientELN Client
GiuntiGiuntiLMS/LCMSLMS/LCMS
ELN ClientELN Client
Sanoma Sanoma WSOYWSOY LMS/LCMSLMS/LCMS
ELN ClientELN Client
MessagingMessagingServerServer
EUNEUNLMS/LCMSLMS/LCMS
ELN ClientELN Client
Brok. SystemBrok. SystemCentral serv.Central serv.
ELN ClientELN Client
DigitalbrainDigitalbrainLMS/LCMSLMS/LCMS
ELN ClientELN Client
GiuntiGiuntiLMS/LCMSLMS/LCMS
ELN ClientELN Client
Sanoma Sanoma WSOYWSOY LMS/LCMSLMS/LCMS
ELN ClientELN Client
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Federated Search
MessagingMessagingServerServer
EUNEUNLMS/LCMSLMS/LCMS
ELN ClientELN Client
Brok. SystemBrok. SystemCentral serv.Central serv.
ELN ClientELN Client
DigitalbrainDigitalbrainLMS/LCMSLMS/LCMS
ELN ClientELN Client
GiuntiGiuntiLMS/LCMSLMS/LCMS
ELN ClientELN Client
Sanoma Sanoma WSOYWSOY LMS/LCMSLMS/LCMS
ELN ClientELN Client
MessagingMessagingServerServer
EUNEUNLMS/LCMSLMS/LCMS
ELN ClientELN Client
Brok. SystemBrok. SystemCentral serv.Central serv.
ELN ClientELN Client
DigitalbrainDigitalbrainLMS/LCMSLMS/LCMS
ELN ClientELN Client
GiuntiGiuntiLMS/LCMSLMS/LCMS
ELN ClientELN Client
Sanoma Sanoma WSOYWSOY LMS/LCMSLMS/LCMS
ELN ClientELN Client
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MessagingMessagingServerServer
Brok. SystemBrok. SystemCentral serv.Central serv.
ELN ClientELN Client
ELN ClientELN Client
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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