LigADOS: interligação de conjuntos de dados em plataformas de dados abertos na web semântica

Abstract

The Open Data movement has been guided by the need to comply with laws to enforce transparency and accountability, which establish the need to make public and private sector activities data available to citizens and the society in general, as well as results of scientific research. The availability of data to the public can vary from a simple website on the Internet to sophisticated data access applications. In this context, one of the options is the construction of an open data portal using open data platforms software, such as CKAN. In recent years, there has been a rapid proliferation of these portals. On open data platforms, datasets are usually described by metadata with little semantics. As a result, datasets often remain as “data silos”, with no explicit connection or data integration mechanism, making it difficult for users to locate and interrelate relevant data sources. In contrast, the Semantic Web focuses on a way of modeling and representing data in an easier manner to establish interrelationships between data, accompanied by richer descriptors. Based on this scenario, this dissertation presents LigADOS, an approach to establish interconnections between datasets considering their content and associated metadata. LigADOS is based on the principles of the Semantic Web and associated linked data solutions and technologies, to create interconnections between open datasets, modeled as linked data and published on data portal platforms such as CKAN and others. The feasibility of the proposal is evaluated through a prototype using datasets extracted from instances of real data portals. Without the use of LigADOS, only relations generated between datasets are observable, from elements of coincident metadata, which are not usually associated with vocabularies, ontologies or thesaurus. LigADOS supports the generation of several interlinkages between datasets, which are based on meanings defined in vocabularies, ontologies or thesaurus, providing support for more expressive results in responses to searches and queries, in addition to support for navigation through data interlinkages. The results of using LigADOS suggest that there are interlinkages between datasets that are not explicit to the public; just as there are datasets that initially seem to have interlinkages, but when going deeper into the semantics of the data, the supposed interlinkages are not verified.