Workshop Bridging the Gap between Web 2.0 and Semantic Web (SemNet), ESWC 2007

1. State of the Art Problem Statement SWiM Knowledge Representation Services Conclusion
Towards Scientific Collaboration in a Semantic Wiki
Bridging the Gap between Web 2.0 and Semantic Web
Christoph Lange
Jacobs University Bremen
(formerly International University Bremen)
June 7, 2007
Ch. Lange (Jacobs University Bremen) Towards Scientific Collaboration in a Semantic Wiki June 7, 2007 1

2. State of the Art Problem Statement SWiM Knowledge Representation Services Conclusion
Wikis for Science
Current scientific wikis:
Wikipedia (partly)
PlanetMath (domain-specific)
...
Easy to create and link knowledge items
⇒ wikis also suitable for non-public research
projects
Scientific services currently not available
Ch. Lange (Jacobs University Bremen) Towards Scientific Collaboration in a Semantic Wiki June 7, 2007 2

3. State of the Art Problem Statement SWiM Knowledge Representation Services Conclusion
Semantic Wikis
Conventional wikis do not understand the knowledge graph they
contain
Semantic wikis address this problem:
usually: 1 page = 1 real-world concept
pages and links typed with terms from ontologies
Semantic wikis are appropriate base system for community-authored
knowledge models:
support stepwise formalisation workflow
offer enhanced navigation and search
Examples: Semantic MediaWiki [KVV06], IkeWiki [Schaffert06], . . .
Ch. Lange (Jacobs University Bremen) Towards Scientific Collaboration in a Semantic Wiki June 7, 2007 3

4. State of the Art Problem Statement SWiM Knowledge Representation Services Conclusion
Semantic Services for Science
Foster collaboration in a scientific community – e. g.:
suggesting topics of interest to learners
manage dependencies during development
Both issues solved on the semantic web, but not in semantic wikis
Wiki extensions for learning exist [Reinhold06], but do not utilise
knowledge contained in the wiki pages!
Why are semantic wikis not semantic enough?
Because they are not really built on ontologies!
Ontologies are optional mostly; ontology support is too generic
⇒ model generic ontology of (scientific) domain knowledge, design
services on top of that abstraction layer
Ch. Lange (Jacobs University Bremen) Towards Scientific Collaboration in a Semantic Wiki June 7, 2007 4

5. State of the Art Problem Statement SWiM Knowledge Representation Services Conclusion
SWiM, a Semantic Wiki for Mathematics
SWiM prototype: IkeWiki [Schaffert06] + OMDoc [Kohlhase06]
editing, presentation, navigation; partly ontology-based
Ch. Lange (Jacobs University Bremen) Towards Scientific Collaboration in a Semantic Wiki June 7, 2007 5

6. State of the Art Problem Statement SWiM Knowledge Representation Services Conclusion
Structural Semantic Markup
Structural semantic markup: common way to represent scientific
knowledge
Markup languages available for:
Mathematics: Content MathML, OpenMath, OMDoc, . . .
Physics: PhysML
Chemistry: CML
Geodata: GML, SensorML, MarineML, ESML, . . .
From top to bottom (roughly): less structures, more data
For OMDoc, e. g., there are services for learning assistance, semantic
search, publishing, theory management, proof verification, . . .
Technology transfer in progress [HKS06]
Ch. Lange (Jacobs University Bremen) Towards Scientific Collaboration in a Semantic Wiki June 7, 2007 6

7. State of the Art Problem Statement SWiM Knowledge Representation Services Conclusion
Scientific Knowledge Representation
Three levels of scientific knowledge [Kohlhase06]:
Objects symbols, numbers, equations, molecules, . . .
Statements axioms, hypotheses, measurement results, examples;
relationships: “proves”, “defines”, “exemplifies”, . . .
Theories collections of interrelated statements, determine context:
“What does the symbol h mean?”
Successfully applied to mathematics (OMDoc), transferred to physics
[HKS06]
Ch. Lange (Jacobs University Bremen) Towards Scientific Collaboration in a Semantic Wiki June 7, 2007 7

8. State of the Art Problem Statement SWiM Knowledge Representation Services Conclusion
Bringing Ontologies into Play
Markup language for expressing scientific knowledge available
Make it semantic web aware – formalise it in an ontology!
Partly done for OMDoc; further steps: extending, generalising
imports
Theory
lives in contains-1 Concept depends on
Statement
Symbol
defined by
Definition
Ch. Lange (Jacobs University Bremen) Towards Scientific Collaboration in a Semantic Wiki June 7, 2007 8

9. State of the Art Problem Statement SWiM Knowledge Representation Services Conclusion
Where is the Knowledge in a Wiki?
Semantic wiki: One page = one concept
SWiM: One page = one statement or theory
(small, reusable pages, but not too small)
Semantic Web tools need more explicit representation of the
knowledge (extract from markup!)
Example
A wiki page: Extracted RDF triples (= graph):
proves
<omdoc> Proof Theorem
<proof id="pyth-proof" type type
for="pythagoras"> proves
... pyth-proof pythagoras
</proof>
</omdoc>
<pyth-proof, rdf:type, omdoc:Proof>
<pyth-proof, omdoc:proves, pythagoras>
(omdoc:* → OMDoc document ontology)
Ch. Lange (Jacobs University Bremen) Towards Scientific Collaboration in a Semantic Wiki June 7, 2007 10

10. State of the Art Problem Statement SWiM Knowledge Representation Services Conclusion
Learning Assistance
Added value analysis [KM07] for the “core
problem” of helping a scholar to understand a
topic.
setting: Course modules (= theories) connected
by prerequisite links (= theory imports)
1 show navigation bar with direct links from
current topic to other topics, grouped by type
sacrifice: indirect prerequisites not accessible
directly
2 explore direct and indirect prerequisites (via
reasoning)
sacrifice: too many irrelevant links
Ch. Lange (Jacobs University Bremen) Towards Scientific Collaboration in a Semantic Wiki June 7, 2007 11

11. State of the Art Problem Statement SWiM Knowledge Representation Services Conclusion
Learning from the Community
New core problem: pre-select relevant prerequisite links!
1 Do it the social way: record what other users clicked
sacrifice: What if my needs are different from others’ ?
2 Give a better, personalised estimate!
Single-user context: determine user’s previous knowledge (user model)
[M+ 06]
Use the community power: find out to which sub-community the user
belongs
e. g. concerning communities of practice [Müller07]
Ch. Lange (Jacobs University Bremen) Towards Scientific Collaboration in a Semantic Wiki June 7, 2007 12

12. State of the Art Problem Statement SWiM Knowledge Representation Services Conclusion
Mission
Implement prototypes of these services and evaluate them in long-term
case studies.
Science Our group is working on the cross-domain integration of
scientific markup languages
test SWiM+ in a heterogeneous environment,
particularly dependency management
Education General Computer Science course from fall 2007
Convert and import lecture notes
evaluate learning assistance
Ch. Lange (Jacobs University Bremen) Towards Scientific Collaboration in a Semantic Wiki June 7, 2007 13

13. State of the Art Problem Statement SWiM Knowledge Representation Services Conclusion
The Big Picture
Easy Editing
Search
Proof for … 1
1 z −2 ?
2
pythagoras ∫−∞ e d ?
partial-diff-eqn ¿
proton 1.-------
---------
2.-------
---------
SWiM+ Publishing
Learning
Assistance
Change
Management
<xml>
...
</xml>
Note: many services are independent from a particular scientific domain!
Ch. Lange (Jacobs University Bremen) Towards Scientific Collaboration in a Semantic Wiki June 7, 2007 14

14. State of the Art Problem Statement SWiM Knowledge Representation Services Conclusion
Related Work
se(ma)2 wi [Zinn06]: Semantic MediaWiki . . .
. . . fed with OMDoc-formatted knowledge from ActiveMath
e-learning environment
Categories and learning metadata are used . . .
. . . but structural semantic got lost
A
Formulae in presentational LTEX, untyped links
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15. State of the Art Problem Statement SWiM Knowledge Representation Services Conclusion
Managing Dependencies: Support the Community
Recall the use case: Stein’s theory R depends on Ton’s theory G. Ton
makes a change; Stein should be informed about that.
1 Tell Stein: a page your page depends on has been changed.
benefit: better than “recent changes”
sacrifice: Stein himself must figure out whether the change broke
something
2 Find out whether Ton changed the semantics of G (just ask him)
sacrifice: Ton has to classify his change.
Ch. Lange (Jacobs University Bremen) Towards Scientific Collaboration in a Semantic Wiki June 7, 2007 16

16. State of the Art Problem Statement SWiM Knowledge Representation Services Conclusion
Managing Dependencies
Previous sacrifices: users themselves must reason
too much
1 Automatically compute “long-range effects” of
changes
locutor [Müller06] can!
can also do some required fixes <xml>
...
Integrate it into the backend! </xml>
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