A Plug-In Architecture for Graph Based Collaborative Modeling Systems

AIED 2003

COLLIDE research groupUniversity of Duisburg-Essen, Germany

A Plug-In Architecture for Graph Based Collaborative Modeling SystemsNiels Pinkwart

Niels PinkwartUniversity of Duisburg-Essen

[email protected] of 22

A Plug-In Architecture for Graph Based Collaborative Modeling Systems

Sharing and commenting of resources as a basic means to support learning

• Representation modes of these resources differ

• Frequently used mode forresources and means ofcommenting: graph based




Augmentation of argumentation tools: ”Collaborative Mind Tools“

• Shared computational objects to think (work) with

• Enriched with rules and interpretation patterns• Semantic processing of information• Promising and easily possible: integration with

modeling languages




Cool Modes(Collaborative Open Learning and Modeling Environment)

Central aims:• Means to mix different externally defined

conceptual representations; plug-in domain semantics

• Work without loosing domain or social context• High degree of flexibility (also for cooperation)

without loss of processing power




System Evaluation • Single plug-ins evaluated in school settings• Questionnaire for extension mechanism

planned

Outlook• Model transformations• Metadata and awareness components



Systemstructure


Synchronisation: MatchMaker

Workspaces (shared)

Plug-Ins (dynamic use)

intra-toolinteroperability



Reference Frames: Principles

• Encapsulate semantic units / languages, ”microworlds“ that can be mixed

• Offer shareable entities for work (or: thinking)• Contain objects, relationships, constraints and

interpretation patterns• Have a UI that relies on direct manipulation• Are externally defined and ”pluggable“




Reference Frames: Structure

Realisations:

- Code based (Java) - Data based (XML)




Reference Frames: XML example (Petri Nets)

<ReferenceFrame> <TemplateClass>DefaultReferenceFrame</TemplateClass> <Objects> <Node> <ClassRef>PlaceNode</ClassRef> </Node> <Node> <ClassRef>TransitionNode</ClassRef> </Node> <Edge> <ClassRef>PetriEdge</ClassRef> </Edge>





<Objects> … <Rule Message=“It is not allowed to draw ...”> <EdgeRule weight=“0”> <NodeRef>PlaceNode</NodeRef> <NodeRef>PlaceNode</NodeRef> <EdgeRef>PetriEdge</NodeRef>

</EdgeRule></Rule> <Metadata> <Name>Petri Net Frame</Name> <Icon>petri32.gif</Icon> <Package>info.collide.coolmodes.plugins.petri</Package> </Metadata></ReferenceFrame>





<Objects> … <Rule Message=“Do not connect Places to Places”> <EdgeRule weight=“0”> <NodeRef>PlaceNode</NodeRef> <NodeRef>PlaceNode</NodeRef> <EdgeRef>PetriEdge</NodeRef>

</EdgeRule></Rule> <Metadata> <Name>Petri Net Frame</Name> <Icon>petri32.gif</Icon> <Package>info.collide.coolmodes.plugins.petri</Package> </Metadata></ReferenceFrame>




Reference Frame based interpretation : How does Cool Modes analyse user-generated structures and how does it react?

• Workspace content is a graph (N,E)

• Interpretation: Ip(N,E)

• Generic information about elements is available to all the Frames

• Generic Interpretation by a Frame F: Ipgen (F,N,E)




Reference Frame based interpretation

• Each Frame F has sets Knows(F) Defines(F).

• (NF,EF) largest subgraph of (N,E) with typesIn(NF) Knows(F) and typesIn(EF) Knows(F)

• Semantically enriched interpretation: Ipsem (F, NF,

EF)





• Each Frame F has sets Knows(F) Defines(F).

• (NF,EF) largest subgraph of (N,E) with typesIn(NF) Knows(F) and typesIn(EF) Knows(F)

• Semantically enriched interpretation: Ipsem (F, NF,

EF)

• Overall, with set of Frames and aggregation :


)E,NF,(IpE)N,(F,Ip:E)Ip(N, FFsemgenF




Events upon node or edge...• Adding • Removal • Movement • Model change


... are distributed to• Neighbours (local) • Reference Frames

(global)




System Evaluation • Several reference frames evaluated in school

settings, results used for usability improvement• Questionnaire for evaluation of the extension

mechanism itself planned

Outlook• Model transformations • Inter-operability between Reference Frames

going beyond Knows(F)• Metadata and awareness components



Questions?

http://www.collide.info


A Plug-In Architecture for Graph Based Collaborative Modeling Systems

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