Evaluating the quality of the LOD cloud: An empirical investigation

Abstract

The increasing adoption of the Linked Data principles brought with it an unprecedented dimension to the Web, transforming the traditional Web of Documents to a vibrant information ecosystem, also known as the Web of Data. This transformation, however, does not come without any pain points. Similar to the Web of Documents, the Web of Data is heterogenous in terms of the various domains it covers. The diversity of the Web of Data is also reflected in its quality. Data quality impacts the fitness for use of the data for the application at hand, and choosing the right dataset is often a challenge for data consumers. In this quantitative empirical survey, we analyse 130 datasets (≈ 3.7 billion quads), extracted from the latest Linked Open Data Cloud using 27 Linked Data quality metrics, and provide insights into the current quality conformance. Furthermore, we publish the quality metadata for each assessed dataset as Linked Data, using the Dataset Quality Vocabulary (daQ). This metadata is then used by data consumers to search and filter possible datasets based on different quality criteria. Thereafter, based on our empirical study, we present an aggregated view of the Linked Data quality in general. Finally, using the results obtained from the quality assessment empirical study, we use the Principal Component Analysis (PCA) test in order to identify the key quality indicators that can give us sufficient information about a dataset's quality.

A Scalable Framework for Quality Assessment of RDF Datasets

“…Furthermore, we also provide a Docker image of the system integrated within the BDE platform 11 -an open source Big Data processing platform allowing users to install numerous big data processing tools and frameworks and create working data flow applications.…”

An Assessment of Adoption and Quality of Linked Data in European Open Government Data

“…[14] analysed best practice adoption in terms of linking, vocabulary usage, and metadata provision in different topical domains from a sample of 1014 datasets (including 183 from government) crawled in 2014. [4] evaluated the quality of a crawl seeded from the LOD cloud 2014 dataset of 130 datasets, totalling approximately 3.7 Billion quads. Our study applies a subset of the metrics used in these previous works on a much more recent (March 2019) corpus of open government datasets.…”

“…(i) Unlike [7,14], we did not use crawling to construct our corpus. Our approach was similar to [4], which used the LOD cloud DCAT descriptions as a starting point. (ii) We considered only datasets that included in their DCAT description the dct:format property.…”

“…This means that we might have missed some datasets that do not come with a data dump distribution in RDF. As [4], we do not consider incorrect format tags. (iv) As we approximated publishers using the host's PLD, we might have lost some information about the actual publishers.…”

“…Open Data Soft, a technology provider in this space, estimates that there are more than 2600 such portals around the world. 3 4. Use URIs to denote things (matching Linked Data principles 1 to 3).…”