2013.07.22 Tom De Nies - METHOD 2013 - Easy Access to Provenance: an Essential Step Towards Trust...

ELIS – Multimedia Lab

Tom De Nies Ghent University – iMinds – MMLab

http://users.ugent.be/~tdenies

@TomDeNies

Easy Access to Provenance: an Essential Step Towards Trust on the Web

Presentation at METHOD 2013

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Easy Access to Provenance: an Essential Step Towards Trust on the Web Tom De Nies (iMinds-MMLab)

22/07/2013

prefix ex: <http://example.org>

entity(ex:Tom, [prov:type=“prov:Person”])

entity(ex:Tom_in_Belgium) specializationOf(ex:Tom_in_Belgium, ex:Tom)

entity(ex:Tom_in_Japan) specializationOf(ex:Tom_in_Japan, ex:Tom)

wasDerivedFrom(ex:Tom_in_Japan, ex:Tom_in_Belgium, ex:travel, -, -)

activity(ex:travel)

activity(ex:departure) activity(ex:arrival)

wasStartedBy(ex:travel, -, ex:departure, 2013-07-21T15:00:00+02:00)

wasEndedBy(ex:travel, -, ex:arrival, 2013-07-22T20:00:00+09:00)

activity(ex:presentation)

wasAssociatedWith(ex:presentation, ex:Tom_in_Japan)

The provenance of today’s talk

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activity(ex:travel)






The provenance of today’s talk

Possible distrust

event due to jetlag!

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With this provenance, the trust assessment score of this talk would be less then ideal

However, that’s why it’s a trust assessment, not a certainty.

Trust me ;-)

Disclaimer

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Introduction to provenance

Lessons learned from literature

Provenance-based trust assessment

Use case: the “Oh, Yeah?”-button

Overview

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Definition:

“Provenance is information about entities, activities, and people

involved in producing a piece of data or thing, which can be used to form assessments about its

quality, reliability or trustworthiness. ”


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The new PROV family of specifications

4 W3C Recommendations:

PROV-DM: Data Model

PROV-Constraints: Constraints for valid PROV

PROV-N: human-readable notation

PROV-O: machine-readable notation

+ 8 Notes

www.w3.org/TR/prov-overview

Standardized provenance

http://www.w3.org/TR/prov-overview



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Overview

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Reputation, reputation, reputation…

Collaborative

Personalized [1]


[1] J. Golbeck and A. Mannes, “Using trust and provenance for content filtering on the semantic web,” in Proceedings of the Models of Trust for the Web Workshop, 2006.

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… but not only reputation!

The provenance matters.

Use a combination of both [2,3]


[2] D. Ceolin, P. Groth, W. R. van Hage, A. Nottamkandath, and W. Fokkink, “Trust evaluation through user reputation and provenance analysis,” in 8th International Workshop on Uncertainty Reasoning for the Semantic Web, 2012, p. 15. [3] H.-S. Lim, Y.-S. Moon, and E. Bertino, “Provenancebased trustworthiness assessment in sensor networks,” in Proceedings of the Seventh International Workshop on Data Management for Sensor Networks. ACM, 2010, pp. 2–7.

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Humans don’t assign trust scores,

they identify distrust events [4].


[4] X. Li, T. Lebo, and D. L. McGuinness, “Provenance based strategies to develop trust in semantic web applications,” in Provenance and Annotation of Data and Processes. Springer, 2010, pp. 182–197.

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Currently, there is no system

that only uses provenance

to make trust assessments. (to the best of our knowledge)


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Overview

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We define 6 criteria:

1. Availability

2. Validity

3. Provenance of provenance

4. Consistency

5. Correctness

6. Reputation

Provenance-based Trust Assessment

Human-understandable Conclusions

vs.

Machine-understandable

Trust score

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PROV-AQ: Access and Query

3 options:

Accessing Provenance on the Web

1. HTTP Link header Link: <provenance-URI>; rel= "http://www.w3.org/ns/prov#has_provenance"; anchor="target-URI", <provenance-service-URI>; rel= "http://www.w3.org/ns/prov#has_query_service"; anchor="target-URI"

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3 options:


2. HTML <link> element <html> <head> <link href="provenance-URI" rel= "http://www.w3.org/ns/prov#has_provenance"> <link href="target-URI" rel= "http://www.w3.org/ns/prov#has_anchor"> <link href="provenance-service-URI" rel= "http://www.w3.org/ns/prov#has_query_service"> </head> <body> ... </body> </html>

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3 options:


3. RDF @prefix prov: <http://www.w3.org/ns/prov#>. <resource-URI> prov:has_provenance <provenance-URI>; prov:has_anchor <target-URI>; prov:has_query_service <provenance-service-URI>;

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Based on PROV-Constraints

http://provenance.ecs.soton.ac. uk/validator/validation/submit

validate : 'Validate'

url : <provenance-URI>

file : <file upload>

statements : <the provenance statements>

Provenance Validation

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Trust cannot be directly derived from validation …

… but it does indicate that the author made an effort!

Provenance Validation

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Coarse-grained: use prov:bundle

A bundle is also an entity, so it’s’provenance can be described!

Fine-grained: use annotations

e.g., “Uncertainty Provenance (UP)” [5] http://semweb.mmlab.be/ns/up up:assertionConfidence up:assertionType

(e.g., up:HumanAsserted, up:MachineGenerated, …)

[5] De Nies, Tom, et al. "Modeling uncertain provenance and provenance of uncertainty in W3C PROV." WWW2013, 2013.

Provenance of Provenance

http://semweb.mmlab.be/ns/up



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Does the provenance correspond to alternative sources?

Normalization/Equivalence [PROV-Constraints]

Provenance Consistency

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Does the provenance correspond to the content?

Feature extraction/comparison

Semantic similarity

Provenance Correctness

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Reputation of provenance source

Reputation of agents, entities

Feed domains to reputation service, e.g., Web of Trust http://mywot.com

Provenance Reputation

http://mywot.com/

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Trust assessment

Accessing & validating provenance


Overview

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Tim Berners-Lee (1997)

“Each browser should have a button labeled ‘Oh, Yeah?’,

that you press when you lose that feeling of trust.”

Use Case: the “Oh, Yeah?”-button

Distrust events!

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Currently:

We support 4 out of the 6 criteria:

1. Availability

2. Validity

3. Provenance of provenance

4. Consistency

5. Correctness

6. Reputation

“Oh, Yeah?” Trust Assessment

Future Work

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“Oh, Yeah?” Visualisation

Discussion: • Still too detailed for novice users!

Future Work: • Adjustable level of detail • Support all 6 criteria • Identify distrust events beforehand • Objective evaluation

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activity(ex:travel)






So where does that leave today’s talk?

Certified by His Royal Highness King Filip of Belgium! (who was crowned yesterday)

Provenance and reputation: a good recipe for trust!

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Available in Chrome Web Store!

http://users.ugent.be/~tdenies

@TomDeNies Co-authors:

• Coppens, S., Verborgh, R., Vander Sande, M., Mannens, E., Van de Walle, R. (Ghent University – iMinds – MMLab)

• Michaelides, D., and Moreau, L. (University of Southampton)

Thank you for your attention!

Oh ? yeah

2013.07.22 Tom De Nies - METHOD 2013 - Easy Access to Provenance: an Essential Step Towards Trust...

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