Community support through the LOR · 2004. 9. 22. · Learning Object Repository (LOR) Service – Each social context provides a LOR service where users can store and manage LOs

2nd Project Review – Växjo (Sweden)September 2004

COLDEX WP6

Community support through the LOR

LTCS (FUELTCS (FUE--UNED)UNED)Beatriz Barros, Beatriz Barros, M. M. Felisa VerdejoFelisa Verdejo ,,

J.Ignacio Mayorga, J.Ignacio Mayorga, TimTim ReadRead, Javier , Javier VelezVelez, , Yolanda Calero, Carlos Yolanda Calero, Carlos CelorrioCelorrio, Emilio Lorenzo, Emilio Lorenzo

COLLIDE (UDUI)COLLIDE (UDUI)Ulrich HoppeUlrich Hoppe, María , María OlingerOlinger, , Niels PinkwartNiels Pinkwart

10.09.2004 2nd Project Review – Växjö (Sweden)

Outline

IntroductionGeneral architecture– View Layer– Model Layer– A Coldex Portal Demo…

A view to relate the components and layers

– Persistence Layer

Further work


Introduction

To support learning groups and communities to work in context; either from a group view, from a task view,..

Social navigation

Learning objectsdescription facilitating co-construction ( reuse & share & enrich..)

Technical requirements– Distributed communities– Modelling approach allowing flexibility, adaptability and evolution


General Architecture

View Layer. For interaction purposes– Actions. Bridge to model layer

Social ManagerLO Repository Knowledge Manager

HIB

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CO

LDE

XP

OR

TAL

KM

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LOR

Ontology

Syn

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nize

rActionsActionsActions

ActionsActionsActions


View Layer Model Layer Persistence Layer

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D.6.3.1D.6.3.1



Model Layer. Handles the execution of all the services that makes up the system– Modules

Social ManagerKnowledge Manager

– ServicesLO RepositorySocial BrowserNewsChatMail…

D.6.3.1D.6.3.1

HIB

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CO

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XPO

RTA

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KM

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LOR

Ontology

Syn

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Persistence Layer. Offers the mechanism to provide persistence for all the storage needs of the system– Data Persistence

Data BaseC-JDBCHibernate

– KnowledgeProtégé OntologyAlgernon

HIB

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TAL

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D.6.3.1D.6.3.1


The Portal

The portal– The portal is a web application that constitutes a

communication and coordination medium for the virtual communities. It provides access, within a context, to the available services

– It consists of Workspaces as an environment where users can interact through the repository, while they develop learning activities, mainly, in a collaborative way. Services that offer interaction means between users both in a direct or indirect way (LOR, Forum, Polls, …)

View Layer


The Social Manager

Social Manager– This module stores all the information related to social

aspects such as the users that can connect to the system, the organisation of groups, previously active sessions…

– Functions:To administrate the system users, register new users and delete old ones.To manage the working sessions of each user (login / logout)

To manage the social model specified by the system administrators.

ChemistryCommunity

Administrator

Teacher

Bencedine

Student

Student

Student

Monitor

Organic Group

Student

Student

Student

Monitor

GlycerineGroup

Student

Student

Student

Monitor

Felisa

Carlos

Beti

Model Layer


The Social Manager

The social Model

– Actor. Represents a user stereotype within the portal– Group Template. Represents a stereotype of a collective of users– User. Represents a real user within the portal– Group. Represents a collective of users fitting a group template

User Actor

Group Group Template

embodies

fits

Model Layer


The Portal

The portal

Model Layer


Chemistry Community LOR

The LOR Service

Learning Object Repository (LOR) Service– Each social context provides a LOR service where users can

store and manage LOs within the Coldex server

– FunctionsTo upload and metadocument objects of a variety of typesSemantic searching and field based searchingTo view the contents of the LOR without having to download it

ChemistryCommunity

Administrator

Teacher

Bencedine

Student

Student

Student

Monitor

Organic Group

Student

Student

Student

Monitor

GlycerineGroup

Student

Student

Student

Monitor

Glycerine Group LOR

Organic Group LOR

Inorganic Group LOR

Model Layer


The LOR Service

The LOR within its social context

– Users, Groups and Actors are abstracted as social units– Each social unit has a social context with a collection of services– LOR is a service

User Actor

Group Group Template

embodies

fits

Social Unit Social Context

Service

Repository ...

nn

n

Model Layer


The Portal

The portal

Model Layer


A Coldex Portal Demo…

A demo…Showing the workspace areaUploading and metadocumenting a new Learning ObjectTo Move/Copy/Delete learning objectsContextual Searching in LOR

– Metadata searching– Semantic Searching

– Join/Create groups and users

Start here!


The Metadata

Several metadata schema are used by partners– A common set as a minimum consensus of metadata– Each partner extends this set defining a new LO type

Model Layer

Find by consensus

Defined by each partner

D.7.2.2D.7.2.2


The Metadata

The Metadata problem– Filling metadata is

Very time consuming and heavy to be done by handA error prone process

– The server and tools can assist automating this process The automatic populating of metadata exploits context info– Resource Spy. Extract info from the resource to upload– Social Spy. Extract info from social context– Workspace Spy. Extract info from workspace area– System Spy. Extract info from system

Model Layer

D.7.2.2D.7.2.2


The Metadata

To exploit extracting capabilities from resources– A mapping schema is included in the packaging model

Model Layer

MyMoon.zip

Manifiest.xml

Contents

<?xml version="1.0" encoding="UTF-8"?><metadata>

<metadataItem name="name">My Moon</metadataItem><metadataItem name="version">1.0</metadataItem><metadataItem name="keyword">coolmodes</metadataItem><metadataItem name="keyword">mymoon</metadataItem><metadataItem name="date">2004/04/16 14:26:53</metadataItem><metadataItem name="language">en</metadataItem><metadataItem name="editors"/><metadataItem name="palettes">Moon</metadataItem><metadataItem name="palettes">Graphical Calculator</metadataItem><metadataItem name="palettes">DrawPalette</metadataItem><metadataItem name="project"/><metadataItem name="activity"/>

</metadata>

<?xml version="1.0" encoding="UTF-8"?><metadata>

<metadataItem name="name">My Moon</metadataItem><metadataItem name="version">1.0</metadataItem><metadataItem name="keyword">coolmodes</metadataItem><metadataItem name="keyword">mymoon</metadataItem><metadataItem name="date">2004/04/16 14:26:53</metadataItem><metadataItem name="language">en</metadataItem><metadataItem name="editors"/><metadataItem name="palettes">Moon</metadataItem><metadataItem name="palettes">Graphical Calculator</metadataItem><metadataItem name="palettes">DrawPalette</metadataItem><metadataItem name="project"/><metadataItem name="activity"/>

</metadata>

D.7.2.2D.7.2.2


A Coldex Portal Demo…

A demo…– Show the workspace area

Continue here!Uploads and metadocument a new Learning ObjectMove/Copy/Delete learning objects

– Search in LORo task contextualizedo workspace contextualized

through metadatasemantic searching

– Join/Create groups and users


task contextualizedqueries

Continue demo!


Knowledge Manager

Knowledge Manager– Manages the conceptual model about the COLDEX

communities and their experimental activities . This component is an abstraction to capture and represent separately the relevant information from the actual code that implements it.

Reification (i.e. To represent explicitly relevant objects of the social and repository components) to provide them with a declarative semanticsTo offer searching facilities exploiting not only instances but also the reified objects and relations.

– We have chosen Protégé as our knowledge representation because of its versatility and ease of use; with two pluginsfor reasoning, Protégé Axiom Language (PAL) and Algernon

Model Layer


The Knowledge Manager

The Knowledge Manager

– Support of several reasoning and query languages (Algernon, Pal,…)– Storage of ontological queries on database– The synchronizer

loads ontology at startingUpdates ontology on demand

KnowledgeManager

PALEngine

SearchEngine

SearchEngineFactory

PALQueryBean AlgernonQueryBean

QueryBean

+ execute (QueryBean query)

AlgernonEngine

<<create>>

<<use>><<use>>

Query Repository

Persistence Layer

DB

Synchronizer

Model Layer


Code To Ontology relationships

Model Layer


The Data PersistencePersistence Layer

Distributed persistence with replicated database

– Persistence Layer. To offer transparency – Hibernate. Object to relational Data Mapping tool– C – JDBC. Database cluster middleware to manage replication– MySQL. Database manager

DB ColdexServer 1

InternetDB ColdexServer 1

DB ColdexServer 1

D.6.3.1D.6.3.1

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MySQL

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Further work

Further work– Integrate services with the tools– Extend some features – Support the activities of the OU Schema – Evaluate the usability of the semantic query functionality– Perform an experimental study of scalability


References

D.6.3.1D.6.3.1

D.7.2.2D.7.2.2

Coldex System Architecture Summary.July, 2004. UNEDVerdejo, M.F Barros, B. Read, T. Mayorga, J.I Vélez, J. Calero, YCelorrio, C. & Lorenzo, E.J.

UNED contribution to Functional Documentation. July, 2004. UNEDVerdejo, M.F.; Barros, B; Mayorga, J.I.; Vélez, J



Model Layer



Model Layer


The Data PersistencePersistence Layer

Distributed persistence with centralized database

– Persistence Layer. To offer transparency– Hibernate. Object to relational Data Mapping tool– MySQL. Database manager

DB

ColdexServer 1

ColdexServer 2

ColdexServer 3

InternetDB

HIB

ER

NA

TE

MySQL

Per

sist

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D.6.3.1D.6.3.1


The KnowledgePersistence Layer

DB

Ontology

Alg

erno

nS

ynch

roni

zer

Knowledge level

– Ontology empty at startingStart loadingUpdate on demandVolatile data. Only in memory for reasoning purposes


Frequently asked questions

Persistence Layer

Why not to use only the persistence mechanism provided by Protégé ?– Some functions do not need to use the knowledge level– These functions are efficiently managed by a relational

scheme– Ontology persistence has a less flexible scheme for storage

Why LDAP approach was discarded?– LDAP is a suitable approach to implement LORs– Other functions require relational capabilities – A Relational scheme is a better approach to implement the

portal


UNED Pilot (formative evaluation)

March-April 2003March-April 2004– System funcionality– Learning improvement– Critical issues for deploymentritical issues for deployment

Organizational levelInfrastructure level

Documents

Community support through the LOR · 2004. 9. 22. · Learning Object Repository (LOR) Service – Each social context provides a LOR service where users can store and manage LOs