LODStats is a tool that collects and publishes statistics about Linked Open Data datasets. It gathers 32 statistical metrics about RDF datasets, such as the number of triples, entities, and literals. It can be used to understand datasets and determine their suitability for applications and visualizations. LODStats has a core Python module, a web interface, and publishes the extracted statistics as RDF using the RDF DataCube vocabulary. It allows users to search and explore dataset linkages and facets of the statistical metadata.

1. Linked Open Data Statistics:
Collection and Exploitation
Ivan Ermilov, Michael Martin,
Jens Lehmann, Sören Auer

2. Agenda
● Why LODStats?
● Architecture
● Core Module
● Web Interface
● RDF DataCube

3. Why LODStats?
● Evaluate RDF datasets
● Gathers 32 statistical criteria such as:
– Number of triples, entities, literals...
– Average string length
– Vocabularies, classes used
● Helps you understand your data
● Generates VoID descriptions

4. Why LODStats?
LODStats can answer the following questions:
● Which visualization is suitable for my dataset?
– Does data contain RDF DataCubes?
– Does data contain geospatial information?
– What is the class hierarchy depth?
● Is it suitable for my application?
– Is it linked to DBpedia?
– Is it the largest existing dataset in this domain?

5. LODStats Architecture
https://github.com/AKSW/LODStats
https://github.com/AKSW/LODStats_WWW

6. LODStats: Core Module
● Python module (tested on Ubuntu 12.04)
● Command line interface
● Do the actual work

7. LODStats: Web Interface
http://stats.lod2.eu/

8. LODStats Features (1)
● General LOD cloud statistics
● Report of warnings and errors for each
dataset
● Report on statistical criteria for each individual
dataset
● Export as VoID and DataCube statistical
metadata
● Dataset linkage explorer
● Search function for datasets, vocabularies,
classes, properties, languages, datatypes

9. LODStats Features (2)
● REST interface for the above search functions
● Linked Data publication of statistics
● SPARQL endpoint to query all extracted
statistics
● CubeViz installation for facet-based browsing
and visualisation of the statistical metadata

10. LODStats: Class Stats
http://stats.lod2.eu/

11. LODStats RDF DataCube
https://github.com/AKSW/LODStats_WWW/blob/master/LODStats-Sparqlify/lodstats.sml

13. LODStats RDF DataCube

14. Thank you for your attention!
Questions?
Ivan Ermilov
iermilov@informatik.uni-leipzig.de