The Dynamic Linked Data Observatory

We monitor Linked Data on the Web since 2012 with the aim to allow for the study of and the experimentation with dynamic Linked Data (aka. distributed knowledge graphs). To this end, we collect frequent, continuous snapshots of a subset of the Web of Linked Data compiled for interestingness and broad coverage.

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About

The Dynamic Linked Data Observatory is a framework to monitor Linked Data over an extended period of time. The core goal of our work is to collect frequent, continuous snapshots of a subset of the Web of Data that is interesting for further study and experimentation, with an aim to capture raw data about the dynamics of Linked Data. The resulting corpora will be made openly and continuously available to the Linked Data research community.

News

Our paper "Observing Linked Data Dynamics" has been shortlisted for the 7-Years Most Influential Paper Award at ESWC 2020 :-)

Datasets

We publish the collected RDF as RDF datasets in N-Quads format and the meta data in log files and N-Triples. The data is available for download roughly right after it got crawled.

Currently, we are working on making the data and meta data available in RDF such that analytical queries can be run on the data using SPARQL. Stay tuned!

Team & Contact

Collaborators:
Alumni:
  • Alexandra Wins
  • Kai Jungel
  • Leonard Lausen
  • Patrick O'Byrne
  • Ahmed Abdelrahman
Google group

Publications

Here is a list of publications by the core team:

Conference Papers

Tobias Käfer, Ahmed Abdelrahman, Jürgen Umbrich, Patrick O'Byrne, Aidan Hogan: "Observing Linked Data Dynamics". In the Proceedings of the 10th Extended Semantic Web Conference (ESWC 2013), Montpellier, France, 26–30 May, 2013. Nominated for the 7-Years Most Influential Paper Award at ESWC 2020

Workshop Papers

Tobias Käfer, Alexandra Wins, Maribel Acosta: "Modelling and Analysing Dynamic Linked Data using RDF and SPARQL". Proceedings of the 4th International Workshop on Dataset PROFIling and fEderated Search for Web Data (PROFILES) at the 16th International Semantic Web Conference (ISWC), Vienna, Austria, 21–25 October, 2017. Best Paper Award

Tobias Käfer, Jürgen Umbrich, Aidan Hogan and Axel Polleres: "Towards a Dynamic Linked Data Observatory", In the Proceedings of the Linked Data on the Web WWW2012 Workshop (LDOW 2012), Lyon, France, 16 April, 2012. [pdf]

Posters & Demos

Tobias Käfer, Ahmed Abdelrahman, Jürgen Umbrich, Patrick O'Byrne, Aidan Hogan.
"Exploring the Dynamics of Linked Data". Poster at the 10th Extended Semantic Web Conference (ESWC 2013), Montpellier, France, 26–30 May, 2013. Best Poster Award

Impact

Besides counting the citations of our papers, our impact can be quantified by the number of works that actually used our data for analyses or to build systems. Here is an incomplete list of such works:

Benchmarking Systems

The BEAR Benchmark for benchmarking RDF archives.

Journal Papers

Javier D. Fernández, Jürgen Umbrich, Axel Polleres, Magnus Knuth. Evaluating query and storage strategies for RDF archives. Semantic Web 10(2): 247-291 (2019)

Conference Papers

Mohammad Abdel-Qader, Ansgar Scherp and Iacopo Vagliano. Analyzing the Evolution of Vocabulary Terms and Their Impact on the LOD Cloud. In: Proceedings of the 15th European Semantic Web Conference (ESWC). 2018

Chifumi Nishioka and Ansgar Scherp. Keeping linked open data caches up-to-date by predicting the life-time of RDF triples. In: Proceedings of the International Conference on Web Intelligence (ICWE) 2017.

Johann Schaible, Thomas Gottron and Ansgar Scherp. TermPicker: Enabling the Reuse of Vocabulary Terms by Exploiting Data from the Linked Open Data Cloud. In: Proceedings of the 13th European Semantic Web Conference (ESWC). 2016.

Javier D. Fernández, Jürgen Umbrich, Axel Polleres and Magnus Knuth. Evaluating Query and Storage Strategies for RDF Archives. In: Proceedings of the 12th International Conference on Semantic Systems (SEMANTICS). 2016.

Renata Queiroz Dividino, Thomas Gottron and Ansgar Scherp. Strategies for Efficiently Keeping Local Linked Open Data Caches Up-To-Date. In: Proceedings of the 14th International Semantic Web Conference (ISWC). 2015.

Chifumi Nishioka and Ansgar Scherp. Temporal Patterns and Periodicity of Entity Dynamics in the Linked Open Data Cloud. In: Proceedings of the 8th International Conference on Knowledge Capture (K-CAP). 2015.

Thomas Gottron and Christian Gottron. Perplexity of Index Models over Evolving Linked Data. In: Proceedings of the 11th European Semantic Web Conference (ESWC). 2014.

Workshop Papers

Albert Meroño-Peñuela, Peter Wittek and Sándor Darányi. Visualizing the Drift of Linked Open Data Using Self-Organizing Maps. In: Proceedings of the 1st Workshop on Detection, Representation and Management of Concept Drift in Linked Open Data (Drift-a-LOD) at the 20th International Conference on Knowledge Engineering and Knowledge Management (EKAW). 2017.

Chifumi Nishioka and Ansgar Scherp. Information-theoretic Analysis of Entity Dynamics on the Linked Open Data Cloud. In: Proceedings of the 3rd International Workshop on Dataset PROFIling and fEderated Search for Linked Data (PROFILES ’16) co-located with the 13th ESWC. 2016

Thomas Gottron. Of Sampling and Smoothing: Approximating Distributions over Linked Open Data. In: Proceedings of the 1st International Workshop on Dataset PROFIling & fEderated Search for Linked Data (PROFILES) at the 11th Extended Semantic Web Conference (ESWC). 2014.

Renata Queiroz Dividino, Thomas Gottron, Ansgar Scherp and Gerd Gröner. From Changes to Dynamics: Dynamics Analysis of Linked Open Data Sources. In: Proceedings of the 1st International Workshop on Dataset PROFIling & fEderated Search for Linked Data (PROFILES) at the 11th Extended Semantic Web Conference (ESWC). 2014.

Renata Queiroz Dividino, Ansgar Scherp, Gerd Gröner and Thomas Grotton. Change-a-LOD: Does the Schema on the Linked Data Cloud Change or Not? In: Proceedings of the 4th International Workshop on Consuming Linked Data (COLD) at the 12th International Semantic Web Conference (ISWC). 2013.

Posters & Demos

Renata Queiroz Dividino, André Kramer and Thomas Gottron. An Investigation of HTTP Header Information for Detecting Changes of Linked Open Data Sources. In: Proceedings of Posters & Demos at the 11th European Semantic Web Conference (ESWC). 2014.