DBpedia Ontology Session

Making the Semantic Web rock-solid

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Goal of the DBpedia Ontology Session

• bootstrap a Unified Semantic Ontology Space (USOS)
• centrally engineering data quality into the decentral Semantic Web
• DBpedia principle:
• take low coherent data (Wikipedia) and transform it �into a powerful interconnected knowledge space (DBpedia) �with upgraded usefulness
• DBpedia URIs have provide interoperability in the �Linked Data Cloud for over a decade (coherence)
• How can we apply these principles to ontologies?

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https://archivo.dbpedia.org

Motivation - Why

“So, when is the Semantic Web coming?” �- Thorsten Berger, Professor, Software Engineering in Bochum

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https://archivo.dbpedia.org

How? What’s the lever?

Data Quality - Fitness for Use

• Intrinsic dimensions (syntactic validity, semantic accuracy, consistency, conciseness and completeness)
• Accessibility dimensions (availability, licensing, interlinking, security and performance)
• Contextual & Representational dimensions read Zaveri et al. 2012 - Quality Assessment for Linked Data: A Survey

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https://archivo.dbpedia.org

How? What’s the lever?

Data Quality - Fitness for use

• FAIR - subcategory of data quality
• wide field of opinions
• Data Quality is not measurable directly, quantitative metrics are interpreted as quality indicators
• Data Quality happens at the consumer side

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https://archivo.dbpedia.org

How? What’s the lever?

Who pays the integration tax?

(amount of work needed to get an external artifact working in own system)

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https://archivo.dbpedia.org

How? What’s the lever?

Who pays the integration tax?

• centrally engineering data quality into the decentral Semantic Web �to bootstrap a Unified Semantic Ontology Space (USOS)
• shared effort between:
• publisher/creator
• mediating software (repository, browser or Archivo)
• consumer

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https://archivo.dbpedia.org

Archivo

https://archivo.dbpedia.org/ Download all ontologies�https://databus.dbpedia.org/jfrey/collections/archivo-latest-ontology-snapshots

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https://archivo.dbpedia.org

Archivo

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https://archivo.dbpedia.org

Archivo

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Archivo

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https://archivo.dbpedia.org

Archivo

Mappings:

http://mappings.dbpedia.org/index.php/Main_Page

https://docs.google.com/spreadsheets/d/e/2PACX-1vSZTiEd2FqGPkufIa6kV5mSEyAmT85Uk_SAiLzXU2X6FeXCOgjfklTsjJFtdGP6UBEyU7s5WzqqtYkU/pubhtml

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https://archivo.dbpedia.org

Archivo

Who pays the integration tax?

• Notifying 1400 ontology publishers about the metrics/regulations? SHOULD
• Some development hours at Archivo
• Rating to inform the consumer about caveats

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https://archivo.dbpedia.org

DBpedia Archivo

an augmented Ontology Archive

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Overview

• “Web Archive” for Ontologies
• fully automated: discovery, versioning & testing
• Current Status: 1368 Ontologies (June 2021) → the most exhaustive unified ontology space
• ontology FAIRness → goal is the improvement of (re)usability

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https://archivo.dbpedia.org

Finding an Ontology

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https://archivo.dbpedia.org

Finding an Ontology

• search the website or on the Databus, by text or with SPARQL

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https://archivo.dbpedia.org

Finding an Ontology

• search the website or on the Databus, by text or with SPARQL

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https://archivo.dbpedia.org

Accessing Ontologies

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https://archivo.dbpedia.org

Accessing Ontologies via an API

Accessing all (or any subset) Ontologies¹:

• persistence on the Databus allows usage of the Databus Tool Stack
• Example: Databus Collections → a view on files deployed to the Databus
• Download all the latest versions as N-Triple files:

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Accessing a single Ontology: e.g. https://archivo.dbpedia.org/download?o=http://dbpedia.org/ontology/

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http://archivo.dbpedia.org/download?

o={ontology-URI}

query=$(curl -H "Accept:text/sparql" https://databus.dbpedia.org/denis/collections/latest_ontologies_as_nt)

files=$(curl -H "Accept: text/csv" --data-urlencode "query=${query}" https://databus.dbpedia.org/repo/sparql | tail -n+2 | sed 's/"//g')

while IFS= read -r file ; do wget $file; done <<< "$files"

¹more at https://archivo.dbpedia.org/api

https://archivo.dbpedia.org

Interoperable Ontologies

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https://archivo.dbpedia.org

Interoperable Ontologies

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Debug common Ontology Pitfalls

• problems with correct ontology deployment
• during the addition of an ontology
• ontology star rating for usability
• testing parsing, license and consistency
• extensible SHACL library testing application compliance
• automatic LODE documentation
• compliance to Archivo itself

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0x⭐ Ontology

• not parseable
• no license provided
• (maybe) logically inconsistent

2x⭐ Ontology

• parseable & retrievable
• some license detected
• license only human readable or not unified
• logically inconsistent

4x⭐ Ontology

• parseable & retrievable
• unified license URI
• logically consistent

https://archivo.dbpedia.org

Ontology Reusability

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https://archivo.dbpedia.org

Ontology Reusability

• access even already unavailable ontologies
• cite a certain version of an ontology (identified with a timestamp)
• persistent snapshots of any ontology version

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http://archivo.dbpedia.org/download?

o={ontology-URI}

f={format}

v={version}

e.g. https://archivo.dbpedia.org/download?o=http%3A//www.georss.org/georss/&v=2020.08.10-110000&f=ttl

One REST request:

https://archivo.dbpedia.org

Summary

Archivo …

• … is an exhaustive unified space for ontologies
• … provides findable and easily accessible vocabularies
• … has a star rating and other tests measuring the interoperability and (re)usabilty of ontologies
• … tries to encourage following community standards for ontology metadata

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https://archivo.dbpedia.org

Contribute to Archivo

• add not-yet-discovered ontologies
• check your own ontology and their rating and improve them to get ★★★★
• add SHACL tests checking for the compliance to a certain service
• expert ontology users wanted to form a think tank on how to holistically evolve and validate the web of ontologies at the SEMANTiCS Vocarnival 2021

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https://archivo.dbpedia.org

References

1. Wilkinson, M., Dumontier, M., Aalbersberg, I. et al. The FAIR Guiding Principles for scientific data management and stewardship. Sci Data 3, 160018 (2016). https://doi.org/10.1038/sdata.2016.18
2. J. Frey, D. Streitmatter, F. Götz, S. Hellmann, and N. Arndt. DBpedia Archivo - A Web-Scale Interface for Ontology Archiving under Consumer-oriented Aspects, In Semantic Systems. The Power of AI and Knowledge Graphs, 2020. https://doi.org/10.1007/978-3-030-59833-4_2

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https://archivo.dbpedia.org