The RDF Report Card: Beyond the Triple Count

The RDF Report Card Beyond the Triple Count 26th September 2011 SemTechBiz 2011Leigh Dodds@ldoddshttp://kasabi.comhttp://slideshare.net/ldodds

Triple counts tell us nothing

Triple counts are not a quality indicator

http://dbpedia.org/resource/London

6 triples for Population DensityProperty Count Valuehttp://dbpedia.org/ontology/PopulatedPlace/populationDensity 2 4807.0 4806.971873853451http://dbpedia.org/ontology/populationDensity 2 4806.971874 4807.000000http://dbpedia.org/property/populationDensityKm 1 4807http://dbpedia.org/property/populationDensitySqMi 1 12450

12 triples for Location (1)Property Count Valuegeorss:point 1 51.507222222222225 -0.1275geo:geometry 1 POINT(-0.1275 51.5072)geo:lat 1 51.507221geo:long 1 -0.127500

12 triples for Location (2)Property Count Valuedbpprop:latd 1 51dbpprop:latm 1 30dbpprop:lats 1 26dbpprop:latns 1 Ndbpprop:longd 1 0dbpprop:longm 1 7dbpprop:longs 1 39dbpprop:longew 1 W

~4.6m redundant triples

Triple counts dont indicate utility

http://bbc.co.uk/programmes2.5 million unique users per week, 60 req/s * * http://www.guardian.co.uk/media/pda/2011/apr/06/bbc-yves-raimond

http://bbc.co.uk/programmes Dataset is less than 50 million triples

Beyond the Triple Count

Dataset Information SpectrumLow Detail High DetailSummary and overview Detailed data modelof dataset content documentation & guides

Dataset Information SpectrumLow Detail High DetailSummary and overview Detailed data modelof dataset content documentation & guides More Information

Dataset Information SpectrumLow Detail High DetailMetadata ● Title, Description ● Provenance ● Publication dates ● Licensing ● Usage cues ● Related datasets

Dataset Information SpectrumLow Detail High DetailScope ● What types of entity? ● How many of each type? ● Coverage ● Geographic ● Events (time)

Dataset Information SpectrumLow Detail High DetailStructure ● URI Scheme ● Vocabulary meshing ● How is a person described?

Dataset Information SpectrumLow Detail High DetailInternals ● List of Schemas & RDF terms ● Class/property usage counts ● Triple counts ● Named graph structure ● Source files

RDF Report Card Example

Summarising Content of a Dataset● Find all classes in all datasets in Kasabi● Tag each class against a pre-defined set of categories ● Customized version of top-level schema.org classes● Generate a report card for each dataset listing types of entity

Report Card Categories

Ordnance Surveyhttp://beta.kasabi.com/dataset/ordnance-survey-linked-data

BBC Musichttp://beta.kasabi.com/dataset/bbc-music

British National Bibliographyhttp://beta.kasabi.com/dataset/british-national-bibliography-bnb

NHS Performance Datahttp://beta.kasabi.com/dataset/nhs-performance-data

Summary● Triple counts tell us nothing● Vital to present the quality & utility of our data ● Data publishing platforms should support this● "Progressive disclosure" ● Right detail at the right time● Dataset analysis can generate useful summaries ● e.g. an RDF report card

http://blog.kasabi.com	650
http://blog.ldodds.com	514
http://paper.li	65
http://www.semanticaweb.info	20
http://a0.twimg.com	4
http://a0.twimg.com	4
http://iricelino.org	3
http://us-w1.rockmelt.com	3
https://twitter.com	3
http://twitter.com	1

The RDF Report Card: Beyond the Triple Count

by Leigh Dodds on Sep 26, 2011

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