Multi-synchronous Collaborative Semantic

Wikis

Charbel Rahhal, Hala Skaf-Molli, Pascal Molli, Stéphane Weiss

Inria Nancy-Grand EstNancy University, France

Pascal Molli

Context

Wikis are emblematic of the Web 2.0 It is a collaborative tool :

The web is a Read/Write space Web content is built by users : they produce, but

they also communicate and coordinate through the wiki

It is a social tool : it transforms community of strangers into a

community of collaborators And wikipedia is really amazing...

Semantic wikis

Next, semantic queries can be performed: [[LocatedIn::Europe]][[HasCapital::Paris]] Return the semantic wiki page « France ».

Wikis can be used as knowledge base used by humans and computers...

Problems

As a collaborative editing tool, wikis does not support Multi-synchronous editing

[Dourish95] : Working activities proceed in parallel(multiple streams of activity), during which time the participants are disconnected (divergence occurs); and periodically their individual efforts will be integrated (synchronization) in order to achieve a consistent state and progress the activity of the group".

From a single semantic wiki server to a network of semantic wiki server

A real problem ? Yes especially for semantic wikis...

No transactional change support : Impossible to change several semantic wiki pages atomically

Semantic wikis restructuration requires to change many pages atomically

Intermediate state are visible to users and reasonners !

No process support: How to implement a simple edit/review/publish

process ? Semantic wikis allow to build ontology, quality of

the ontology is dependant of the process used to build this ontology.

How to provide multi-synchronous editing into semantic wikis ?

It is enough to manage semantic pages with Distributed Version Control Systems such as Git, Mercurial, Bazaar...

No : DVCS do not currently support Semantic data

types DVCS only ensure Causality, CSCW researchers demonstrated that Causality,

Convergence and Intentions are required for collaborative editing

as in google wave for example.

Our approach : DSMWDistributed Semantic Media Wiki

Build the multi-synchronous editing feature directly inside an existing semantic wiki (SMW)

Multi-synchronous means: A network a semantic wikis servers (DSMW

nodes) An update is produced on one server It is broadcasted to other servers Others servers receives and re-execute it

The system (all network) is correct if it ensures CCI consistency.

DSMW approach

The broadcast is based on the publish/subscribe model

Server administrators can choose what they publish Server administrators can choose what they

consume Correctness is based on the Logoot algorithm

(ICDCS09). Logoot ensure CCI if broadcast ensures causality.

We proved (in the paper) this is true, with our publish/subscribe mechanism.

DSMW ontology

All elements are represented using Semantic wiki pages : available for requests...

How it works ? 2 pages with [[is in::tutorial]] annotations

[[isin::tutorial]]

Create your feeds

Paches are semantics wikis pages

Now subscription and pull from another DSMW node...

Now you can make your own dataflows

Conclusion

DSMW is an extension of SMW in order to allow multi-synchronous editing

Isolated work and Transactional changes Dataflows

DSMW = SMW + Logoot + publish/subscribe DSMW ensures CCI consistency DSMW stores its data as semantic pages in an

ontology: Allows requests on pages and history of pages,

exports... LGPL : https://dsmw.org (in construction...)

Perspectives

Use the ontology of DSMW to compute new metrics for awareness

Compute existing divergence metrics Compute new ones specific to fully decentralized

work