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Web Science & TechnologiesUniversity of Koblenz ▪ Landau, Germany
Provenance in the Semantic Web
Steffen Staab
Joint work withSimon Schenk, Renata Dividino, Christoph Ringelstein
Steffen [email protected]
Summer School Semantic Web2
WeST
Semantic Web Web Retrieval Interactive Web Multimedia Web Software Web
Institut WeST – Web Science & Technologies
eGovernment eMedia eScience eOrganizations ePerson
Institute for Computer Science
Institute for Information Systems
Leibniz Institute for Social Sciences (GESIS)
Steffen [email protected]
Summer School Semantic Web4
WeST
How to loose 1,000,000,000 US$ in half a day
Via @Bauckhage
Steffen [email protected]
Summer School Semantic Web5
WeST
+++ „Los Angeles (dpa) – In der kalifornischen Kleinstadt Bluewater soll es nach einem Bericht des örtlichen Senders vpk-tv zu einem Selbstmordanschlag gekommen sein. Es habe in einem Restaurant zwei Explosionen gegeben...“ +++
German Press Agency DPA, 10 Sep 2009
Steffen [email protected]
Summer School Semantic Web7
WeST
Hoaxbetter check who said what when and
whether you actually want to trustsome information
Loosing your reputation quickly…
Steffen [email protected]
Summer School Semantic Web8
WeST
Defining Provenance
Provenance … means the origin… of something, or the history of the ownership or location of an object. The term was …used for works of art, but is now …
including science and computing. … In most fields, the primary purpose of provenance is to
confirm or gather evidence as to the time, place, and—when appropriate—the person responsible for the creation, production, or discovery of the object.
This will typically be accomplished by tracing the whole history of the object up to the present
http://en.wikipedia.org/wiki/ProvenanceMay 31, 2011
Steffen [email protected]
Summer School Semantic Web9
WeST
The situation…
Call to Ontoprise from an insurance company:„Can you integrate our 5000 databases?“
EU IP experience (Large Engineering Company):„oh, we just found another PC that has several tens of thousands of relevant documents“
Linked open data cloud
Steffen [email protected]
Summer School Semantic Web10
WeST
Some of the problems…
I have this piece of data.Can I actually believe it? Default answer: Find some expert and ask him.
I have this inconsistency in my data.Who has introduced it and why? Default answer: Try to find it in the sources.
I have this piece of data. How can I use it? Can I show it to anyone? Default answer:
• You are not allowed to do anything with it. Just throw it away.
Steffen [email protected]
Summer School Semantic Web11
WeST
Two Types of Provenance Knowledge
Provenance labels for facts
Which authority?
Which confidence?
When?
Who? Which privileges?
Bluewater is a City
Steffen [email protected]
Summer School Semantic Web12
WeST
Two Types of Provenance Knowledge
Provenance labels for facts Open Provenance Model RDF graph representing
Who did• what• when• why• …
to a data item
„ex post“ workflow instance audit/re-enact
Which authority?
Which confidence?
When?
Who? Which privileges?
admission prepareshare
1 5exami-nation
exami-nation
2askingpermit
43
Bluewater is a City
Steffen [email protected]
Summer School Semantic Web13
WeST
SPARQL QUERYINGUSING PROVENANCE
R. Dividino, S. Sizov, S. Staab, B. Schüler. Querying for Provenance, Trust, Uncertainty and other Meta Knowledge in RDF. In: Journal of Web Semantics. Elsevier, 7(3), 2009, pp. 204-219.
Steffen [email protected]
Summer School Semantic Web14
WeST
Representing Provenance Using URIs
http://bluewater.us a dbpedia:city.http://bluewater.us assertedBy http://neverest.de
BUT:http://bluewater.us a dbpedia:fakecity.http://bluewater.us assertedBy http://dpa.de
Who said what?
Steffen [email protected]
Summer School Semantic Web15
WeST
Representing Provenance Using URIs - 2
http://neverest.de/bluewater a dbpedia:city.http://neverest.de/bluewater assertedBy
http://neverest.de
http://dpa.de/bluewater owl:sameAshttp://neverest.de/bluewater.
http://dpa.de/bluewater a dbpedia:fakecity.http:// dpa.de/bluewater assertedBy http://dpa.de
What is the meaning of owl:same as now forprovenance?
Steffen [email protected]
Summer School Semantic Web16
WeST
Representing Provenance Using Named Graphs
http://dpa.de/ontology{ dbpedia:locatedIn rdf:domain dbpedia:company.dbpedia:locatedIn rdf:range dbpedia:city. …. }
http://neverest.de/kb{ http://bluewater.us a dbpedia:city.
http://vkptv.com a dbpedia:company. }
http://dpa.de/provenance{ http://dpa.de/ontology dpa:lrm „2000-01-01“.http://dpa.de/ontology dpa:trust „highest“.http://neverest.de/kb dpa:lrm „2009-09-09“.http://neverest.de/kb dpa:trust „lowest“. }
Steffen [email protected]
Summer School Semantic Web17
WeST
Ambiguity in Representing Provenance
Distributive Reading Each of the two facts is
assigned low trust
Cumulative Reading Taken together the two
facts are assigned lowtrust
http://neverest.de/kb{ http://bluewater.us a dbpedia:city.
http://vkptv.com a dbpedia:company. }
What does {…http://neverest.de/kb dpa:trust „lowest“. ..} mean?
Both readings are plausible under appropriate circumstances, but • Cumulative reading is harder to specify• Cumulative reading requires closing of sets of facts
(contrast to RDF open world semantics)
Steffen [email protected]
Summer School Semantic Web18
WeST
Meta Knowledge: When?Meta knowledge dimension Set of values plus two operators and such that and are partial orders with a maximum D D , D D
Least Recently Modified DateL xsd:dateTime , L Ls.t.lrm(a L b) = max(lrm(a), lrm(b))lrm(a L b) = min(lrm(a), lrm(b))
Total order, and are dual operators
Steffen [email protected]
Summer School Semantic Web19
WeST
Meta Knowledge: Who?Meta knowledge dimension Set of values plus two operators and such that and are partial orders with a maximum D D , D D
ProvenanceP 2^SOURCES , P Ps.t.prov(a P b) = prov(a) prov(b)prov(a P b) = prov(a) prov(b)
Partial order and are same operator
Steffen [email protected]
Summer School Semantic Web20
WeST
SPARQL: Algebraic Graph Query Languages
SELECT ?city, ?broadcasterWHERE {
?city a ex:city.{ ?broadcaster ex:activeIn ?city }UNION{ ?broadcaster ex:locatedIn ?city }
}
[WWW08,JoWS09]
Steffen [email protected]
Summer School Semantic Web21
WeST
SPARQL: Algebraic Graph Query Languages
SELECT ?city, ?broadcasterWHERE {
?city a ex:city.{ ?broadcaster ex:activeIn ?city }UNION{ ?broadcaster ex:locatedIn ?city }
}
1
2
3
2 13
[WWW08,JoWS09]
Steffen [email protected]
Summer School Semantic Web22
WeST
SPARQL: Algebraic Graph Query LanguagesSELECT ?city, ?broadcasterWHERE {
?city a ex:city.{ ?broadcaster ex:activeIn ?city }UNION{ ?broadcaster ex:locatedIn ?city }
}
1
2
3
2 13
|><|
min
max
2009-09-09
2009-09-09
2009-09-08
2009-09-08 2009-09-09 2009-09-09
2 13
[WWW08,JoWS09]
Steffen [email protected]
Summer School Semantic Web23
WeST
OWL REASONINGUSING PROVENANCE
S. Schenk, R. Dividino, S. Staab.Ontology Debugging Using Provenance.In: Journal of Web Semantics, Elsevier, accepted for publication.
Steffen [email protected]
Summer School Semantic Web24
WeST
Do we trust that bluewater is a real city?
German Press Agency, Highest trust, 2001-01-03
Neverest,Low trust, 2009-09-09
Steffen [email protected]
Summer School Semantic Web25
WeST
Explanation (Pinpointing)Given Ontology O, Axiom , O' O
O' is an explanation (pinpoint) for wrt. O, iffO' andO* for all O* O'
( ) ( )
1
2
3
4
1 2 3 4
Explanation formula?
Steffen [email protected]
Summer School Semantic Web27
WeST
Computation of meta knowledge for OWL
Query: Meta Knowledge for
Compute Pinpointing Formula for wrt O(A1 … Am) … (Z1 … Zn)
Insert Meta Knowledge degrees and operatorsmin(max(lrm(A1), …, lrm(Am)), max(lrm(Z1), …, lrm(Zn))
Evaluate [KI 2009, SWPM2009]
Steffen [email protected]
Summer School Semantic Web29
WeST
(A1 … Am) … (Z1 … Zn)
min(max(lrm(A1)),…, lrm(Am)),…,max(lrm(Z1),…,lrm(Zn))
„Least recently modified?“
Steffen [email protected]
Summer School Semantic Web31
WeST
8
5
9
2
9
2
7
5
7
2
9
Optimized Computation of Provenance
9
3
7 TimeOrder
SyntacticRelevance
Oracle for you: relevant pinpoint
Color codes reachability
Steffen [email protected]
Summer School Semantic Web32
WeST
8
5
9
2
9
2
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5
7
2
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Optimized Computation of Provenance
9
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Steffen [email protected]
Summer School Semantic Web33
WeST
8
5
9
2
9
2
7
5
7
2
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Optimized Computation of Provenance
9
3
7
Steffen [email protected]
Summer School Semantic Web34
WeST
8
5
9
2
9
2
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5
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2
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Optimized Computation of Provenance
9
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Steffen [email protected]
Summer School Semantic Web35
WeST
8
5
9
2
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2
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5
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Optimized Computation of Provenance
9
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Steffen [email protected]
Summer School Semantic Web36
WeST
8
5
9
2
9
2
7
5
7
2
9
Optimized Computation of Provenance
9
3
7Relevant
pinpoint only contained
Steffen [email protected]
Summer School Semantic Web37
WeST
Evaluation: Computing Provenance in Milliseconds
Real-world provenance!
Steffen [email protected]
Summer School Semantic Web40
WeST
create
Middle Rhine Hospital
Health Record
Policies
admission
create
1
Sticky Log create(P1): ukob is allowed to process health records for research purposes.
However, ukob is not allowed to transfer the health records of patients to other organizations.
(P2): The mrh demands that the record is only accessed by ukob afterthe sharing of the health records is approved by the patient and the approval must have been confirmed by a doctor.
Steffen [email protected]
Summer School Semantic Web41
WeST
create
exami-nation
Middle Rhine Hospital
Health Record
Policies
admission
create
create
update
update
update
askingpermit
exami-nation
update
update
prepareshare
de-id.
updateencrypt
fulfill
1 2 3 4 5
Sticky Log:
step (record, {mrh}, {}, create, patient_treatment, 1, {0})step (record, {mrh}, {}, update, examination, 2, {1})reduced (record, hidden, hidden, update, hidden, 4, {2})step (record, {mrh}, {}, de-identified, privacy, 5, {4})attribute (record, de-identified, true, 5)step (record, {mrh}, {ukob}, transfer, research, 6, {5})
Sticky Log
You
share forresearch
update
transfer
transfer
checktransfer
6
Steffen [email protected]
Summer School Semantic Web42
WeST
create
exami-nation
Middle Rhine Hospital
Health Record
Policies
admission
create
create
update
update
update
askingpermit
exami-nation
update
update
prepareshare
de-id.
updateencrypt
fulfill
1 2 3 4 5
Sticky Log:
step (record, {mrh}, {}, create, patient_treatment, 1, {0})step (record, {mrh}, {}, update, examination, 2, {1})reduced (record, hidden, hidden, update, hidden, 4, {2})step (record, {mrh}, {}, de-identified, privacy, 5, {4})attribute (record, de-identified, true, 5)step (record, {mrh}, {ukob}, transfer, research, 6, {5})
Sticky Log
You
share forresearch
update
transfer
transfer
checktransfer
6
permit (6)?
(P3):permit (ID) IF (step (record, _, _, transfer, _, ID, _) AND
attribute (record, de-identified, true, ID)).
Steffen [email protected]
Summer School Semantic Web43
WeST
create
exami-nation
Middle Rhine Hospital
Health Record
Policies
admission
create
create
update
update
update
askingpermit
exami-nation
update
update
prepareshare
de-id.
updateencrypt
fulfill
1 2 3 4 5
Sticky Log:
step (record, {mrh}, {}, create, patient_treatment, 1, {0})step (record, {mrh}, {}, update, examination, 2, {1})reduced (record, hidden, hidden, update, hidden, 4, {2})step (record, {mrh}, {}, de-identified, privacy, 5, {4})attribute (record, de-identified, true, 5)step (record, {mrh}, {ukob}, transfer, research, 6, {5})
Sticky Log
You
share forresearch
update
transfer
transfer
checktransfer
6
permit (6)?
(P3):permit (ID) IF (step (record, _, _, transfer, _, ID, _) AND
attribute (record, de-identified, true, ID)).
Steffen [email protected]
Summer School Semantic Web45
WeST
Data Value lies in
Past Knowing what happened to your data Knowing why it happened to your data
Present Drawing the right conclusions from your data
Future Deciding upon the destiny of your data
Your Strategy is based on Provenance!You better take care!
Steffen [email protected]
Summer School Semantic Web46
WeST
Core References
W3C working group: http://www.w3.org/2011/prov/wiki/Main_Page
IEEE Internet Computing, Vol 15, Issue 1, Jan/Feb 2011Special Issue on „Provenance in Web Applications“http://www.computer.org/portal/web/csdl/abs/html/mags/ic/2011/01/mic2011010017.htm
Journal of Web Semantics, Volume 9, Issue 2, 2011, Special Issue on „Provenance in the Semantic Web“http://www.sciencedirect.com/science/journal/15708268http://websemanticsjournal.org
Steffen [email protected]
Summer School Semantic Web47
WeST
Core References of Our Own WorkProvenance in RDF R. Dividino, S. Sizov, S. Staab, B. Schüler. Querying for Provenance, Trust,
Uncertainty and other Meta Knowledge in RDF. In: Journal of Web Semantics. Special issue on "The Web of Data". Elsevier, 7(3), 2009, pp. 204-219.
Provenance in OWL S. Schenk, R. Dividino, S. Staab, N. Kurz. Ontology Debugging Using
Provenance. In: Journal of Web Semantics. Special issue on “Ontology Dynamics“, Elsevier, 9(3), 2011.
Provenance for Policy Languages C. Ringelstein, S. Staab. Provenance-aware Policy Definition and Execution. In:
IEEE Internet Computing, special issue on Provenance in Web Applications, Jan/Feb 2011, pp. 49-58.
Capturing Provenance in Distributed Workflows C. Ringelstein, S. Staab. DiALog: A Distributed Model for Capturing Provenance
and Auditing Information. International Journal of Web Services Research (JWSR), Idea Group Publishing, 7(2): 1-20, 2010.
Steffen [email protected]
Summer School Semantic Web48
WeST
Thank You!http://west.uni-koblenz.de
See you again at…