LODE user testing session

Posted on April 13, 2012 by S.

Dear Semantic Web and Linked Data people, we need your help!

In order to verify the usefulness and usability of LODE, a web-based tool for the documentation and navigation of OWL and OWL2 ontologies, we are looking for volunteers for a brief online test (30 mins max) whose results will be included in a forthcoming scientific paper about it. The test will be carried out using the well-known web surveys generator Kwik Surveys.

If you feel you can spare a half hour of your time to work through a simple list of questions about OWL ontologies, please go to

http://kwiksurveys.com?u=lodetest

and start the test.

Thank you for your understanding and contribution,

Silvio Peroni
Fabio Vitali

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Document conversion through FRETTA

Posted on March 30, 2012 by S.

Just few days ago, I presented our work on document conversion during the Web Technologies track of SAC 2012, held in Riva del Garda, Italy. It has been a quite interesting conference in the end, with a lot of tracks that, as Stefan (Dietze) said, have concerned “everything which involves bits and bytes”.

In the following text, you can find more data, links and information about our paper.

Title: Embedding semantic annotations within texts: the FRETTA approach

Abstract. In order to make semantic assertions about the text content of a document we need a mechanism to identify and organize the text structures of the document itself. Such mechanism would closely resemble a document-oriented markup language and would be free of the classical constraints of an embedded markup language, having no limitations given by sequentiality, containment, or contiguity of text fragments. In the past years we developed EARMARK, our OWL proposal for expressing arbitrary semantic annotations about the structure and the text content of a document. In this paper we describe FRETTA, our mechanism for rendering arbitrary EARMARK annotations (including non-sequential, non-hierarchical and non-contiguous ones) in XML, bringing into a unifying framework a half dozen of syntactic tricks used in literature to handle overlapping structures in a strictly hierarchical language.

Slides: on Slideshare

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The (Semantic) Web through an FRBR lens

Posted on January 4, 2012 by S.

In December 2011 (by the way, Happy New Year!) I presented a set of slides containing multiple, overlapping, vague and sometimes discording definitions of “Semantic Web” given by very authoritative people in the community. Of course, it is not an easy task to make a clear and unambiguous description of what the Semantic Web is and how it is related to “The Web”.

Recently, I came back to that question and tried to address it through a model commonly used for describing bibliographic resources: FRBR. From this analysis, I came out with my own personal view or, let me say, (yet another) definition of “Semantic Web”, shown in the following picture:

In short, the general idea is that all the “webs” we often refer to – i.e. the Traditional Web, the Social Web and the Semantic Web – actually identify different historical landmarks of the evolution of The Web. Thus, the Semantic Web is the current state of The Web and includes all the scientific fields, researches, theories, communities, tools and technologies that have been part of The Web since its birth.

In a sentence: the Semantic Web is the (today’s) Web.

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Does document markup differ from semantic markup?

Posted on October 18, 2011 by S.

In people’s mind, there still exists a clear distinction between document markup (e.g., XML), that we commonly use for defining the structure of a document, and the semantic markup (e.g., RDF), usually needed when we want to represent, in a particular formalism, the meaning (or, better, a subjective interpretation) of the natural language text of a document1. Document markup and semantic markup are, actually, two sides of the same coin, although most of the people see them living in two separated levels. In fact, even if the document markup is used, in the most cases, for structuring a document, it is not deny to have some markup elements for characterising a range of text to represent a real-world entity, e.g. a person.

Within a text, the element <person>2 and the class foaf:Person3 are (habitually) used for conveying the same meaning, at least from the markup author’s perspective. What really differs between them is that the semantic markup defines a formal representation of their semantics (e.g., in OWL 2 Direct Semantics), while, usually, the document markup does not. In fact, as all the XML-like languages, the markup semantics (that exists but, in this case, is inaccessible) is left to the human interpretation of a natural language definition or, in the worst case, of the markup on its own.

Thus, starting from the following premises:

  • that we use markup for saying something about what it contains/refers to, and
  • that markup semantics always exists, independently from the kinds of markup taken into consideration,

what is the actual profound reason that explain why document markup and semantic markup are considered different?

Footnotes

1. Actually, the document structure on its own can be seen as a particular kind of semantics. In fact, when we speak about a text as structured in terms of its paragraphs, sections, chapters, etc., what we are doing is to associate a semantic role of particular parts of the text.

2. The element person as defined in TEI: http://www.tei-c.org/release/doc/tei-p5-doc/en/html/ref-person.html.

3. The class Person as defined in FOAF: http://xmlns.com/foaf/spec/#term_Person.

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A lode of OWL

Posted on January 13, 2011 by S.

In order to present an ontology to someone else it is important to derive a human-understandable description of it. Of course, ontology editors (such as Protege and NeOn Toolkit) and graphic visualizer (such as OntoViz and KC-Viz) help a lot end-users in understanding an ontology. Moreover, other tools focus on creating a human-readable version of an ontology, such as OWLDoc.

LODE logo

Considering the latter kind of tools, Live OWL Documentation Environment (LODE) is a web service that automatically extracts classes, object properties, data properties, named individuals, annotation properties, general axioms and namespace declarations from an OWL ontology available on the Web, and renders them as ordered lists, together with their textual definitions, in a human-readable HTML page designed for browsing and navigation by means of embedded links.

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