My talk from the Semtech Biz conference in London. I argued that it is time to move beyond discussing size of datasets and encourage a more nuanced view to understand quality and utility. The RDF Report Card is offered as one simple, high-level visualization.

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

2. Triple counts tell us nothing

3. Triple counts are not a quality
indicator

4. http://dbpedia.org/resource/London

5. 6 triples for Population Density
Property Count Value
http://dbpedia.org/ontology/PopulatedPlace/populationDensity 2 4807.0
4806.971873853451
http://dbpedia.org/ontology/populationDensity 2 4806.971874
4807.000000
http://dbpedia.org/property/populationDensityKm 1 4807
http://dbpedia.org/property/populationDensitySqMi 1 12450

6. 12 triples for Location (1)
Property Count Value
georss:point 1 51.507222222222225
-0.1275
geo:geometry 1 POINT(-0.1275 51.5072)
geo:lat 1 51.507221
geo:long 1 -0.127500

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

8. ~4.6m redundant triples

9. Triple counts don't indicate utility

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

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

12. Beyond the Triple Count

13. Dataset Information Spectrum
Low Detail High Detail
Summary and overview Detailed data model
of dataset content documentation & guides

14. Dataset Information Spectrum
Low Detail High Detail
Summary and overview Detailed data model
of dataset content documentation & guides
More Information

15. Dataset Information Spectrum
Low Detail High Detail
Metadata ● Title, Description
● Provenance
● Publication dates
● Licensing
● Usage cues
● Related datasets

16. Dataset Information Spectrum
Low Detail High Detail
Scope ● What types of entity?
● How many of each type?
● Coverage
● Geographic
● Events (time)

17. Dataset Information Spectrum
Low Detail High Detail
Structure ● URI Scheme
● Vocabulary meshing
● How is a person described?

18. Dataset Information Spectrum
Low Detail High Detail
Internals ● List of Schemas & RDF terms
● Class/property usage counts
● Triple counts
● Named graph structure
● Source files

19. RDF Report Card Example

20. 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

21. Report Card Categories

22. Ordnance Survey
http://beta.kasabi.com/dataset/ordnance-survey-linked-data

23. BBC Music
http://beta.kasabi.com/dataset/bbc-music

24. British National Bibliography
http://beta.kasabi.com/dataset/british-national-bibliography-bnb

25. NHS Performance Data
http://beta.kasabi.com/dataset/nhs-performance-data

26. 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