While the web of linked data gets increasingly richer in size and complexity, its use is still constrained by the lack of applications consuming this data. We propose a Web-based tool to build and execute complex applications to transform, integrate and visualize Semantic Web data. Applications are composed as pipelines of a few basic components and… (More)
SPARQL is a powerful query language for Semantic Web data sources but it is quite complex to master. The jigsaw puzzle methaphor has been succesfully used in Blockly to teach programming to kids. We discuss its applicability to the problem of building SPARQL queries, through the presentation of a dedicated Blockly-based visual user interface.
SPARQL queries can be represented in RDF in order to work with them as first-class citizen in Semantic Web applications. The representation used so far, SPIN SPARQL, closely follows the abstract syntax tree, but fails to directly capture the semantics and is hard to work with for query rewriting. Here a novel vocabulary based on SPARQL Algebra is presented.… (More)
SPARQL is a powerful query language for Semantic Web data sources but one which is quite complex to master. As the block programming paradigm has been succesfully used to teach programming skills, we propose a tool that allows users to build and run SPARQL queries on an endpoint without previous knowledge of the syntax of SPARQL and the model of the data in… (More)
The Linked Data Initiative is pushing dataset maintain-ers to publish data online in a highly reusable way through a set of open standards, such as RDF and SPARQL. The amount and variety of available structured data in the Web is increasing but its consumption is still quite limited. In particular applications used to explore linked data are mostly either… (More)
We describe an ongoing co-design project for a collaborative distributed space, based on multi-touch technologies, through which older adults can explore self-produced and on-line multimedia resources for the production of short video clips. The project's main goal is to foster the active participation of older people, already experiencing collaboration in… (More)