]> WP3 contains tasks focused on the transformation of legacy data to RDF and Linked Data and furthermore on the improvement of existing or extracted data especially with respect to schema enrichment and ontology repair. It is complementary to WP4, which is concerned with interlinking several knowledge bases and providing unified views of them. Tasks concerning the triplification of data will be grounded on existing techniques and know-how of the consortium and will be refined during the lifetime of this project and integrated into the LOD2 Stack. Legacy data triplification represents the entry point for legacy systems to participate in the LOD cloud. The members of the Consortium are leading in the development of transformational tools such as Virtuoso Sponger, RDF Views, D2R server, Triplify, and the DBpedia framework, which have received high acceptance in the Linked Data community. 3 WP3 – Knowledge Base Creation, Enrichment and Repair Within this cluster of activities we will develop the technologies necessary to deliver the LOD2 promise – creating an integrated infrastructure for semantic information integration on the Web. In this context, three core challenges need to be addressed: <ol> <li>ensure the knowledge stores scale with the size of the Data Web,</li> <li>provide means for automatic knowledge extraction, alignment, interlinking and</li> <li>enable social collaboration.</li> </ol> 2011-02-28 D3.1.1 – State-of-the-Art Report for Extraction from Structured Sources 2012-04-30 2012-04-30 2011-04-30 2011-04-30 2012-11-30 D3.2.3 – Extension of DBpedia Framework 2011-08-31 D3.3.1 – Release of Knowledge Base Enrichment Algorithms 2012-08-31 D3.3.2 – Release of Knowledge Base Enrichment User Interface 2013-08-31 D3.3.3 – Evaluation of Knowledge Base Enrichment 2011-02-28 D3.4.1 – Report on Automatically Detectable Modelling Errors and Problems 2012-12-31 2013-12-31 2012-02-29 D3.5.1 – Initial Release of Web Linkage Validator 2012-12-31 D3.5.2 – Release of Web Linkage Validator as LOD2 Stack component 2011-04-30 2012-04-30 2012-12-31 M3.3 – Knowledge Base Enrichment and Repair Tools This work package implements the LOD2 knowledge store component needed for managing the Web of Linked Data as a vast database. The starting point is OpenLink Virtuoso and MonetDB on the database side and Sindice on the information retrieval side. The present data volumes handled are around 10 billion RDF triples and the target is over the 1 trillion triples. The approach is scale-out out (physical) complemented with significant scalability improvements in the RDF engine (logical): Physically, when data grows, servers can be added and data redistributed without interruption of service, ibid for server failure. Logically, there is no point answering questions nobody is asking. Therefore the base data is kept as RDF with text indexing and search ranking. Additional inference results or indices for caching joins are made as a by-product of querying; further exploitation of such (partially) materialized inferences through the graph at run-time is to exploit structural correlations in the graphs. 2 WP2 – Storing and Querying Very Large Knowledge bases While WP3 is concerned with making legacy data available via URLs – a prerequisite – and enrichment of knowledge bases, this WP addresses automatic and semi-automatic link creation with minimal human interaction, evolvement of knowledge bases under the aspect of linkage and schema mapping combined with Data Fusion. 4 WP4 – Reuse, Interlinking and Knowledge Fusion