July, 2011

Problems of Linked Data (2/4): Concept

It’s a bit hard to write about Linked Data because of the many changes it’s going through. Therefore, until it becomes stable again, I’ll stick to the official definition of Linked Data, the one that assumes RDF in it. In order to get a clear perspective on the problem, it’s important to analyze the original idea. [...]

Problems of Linked Data (1/4): Identity

Linked Data is defined in Wikipedia as follows: Linked Data describes a method of publishing structured data so that it can be interlinked and become more useful. Linked Data has emerged from the ambitious Semantic Web idea, as the result of the need for more pragmatic approach in which the emphasis is not so much [...]

Problems of the RDF syntax

An RDF syntax (notation) is a concrete syntax for writing (serializing) RDF triples. There are many different notations, some of which are based on existing formats (XML, (X)HTML, JSON), while others use special formats (Turtle). The problems of the RDF model, discussed in the previous posts, are inherited by RDF notations. Various special cases require [...]

The Ultimate Problem of RDF and the Semantic Web

In the previous posts I’ve covered two important problems of the RDF model, related to blank nodes and literals. Here, I’m going to focus on what I think is the key problem of RDF – the problem of the node of an RDF graph. In the RDF: Concepts and Abstract Syntax, a node is defined as follows:  The set [...]

Problems of the RDF model: Literals

Literals are nodes in an RDF graph, used to identify values such as numbers and dates by means of a lexical representation. Literals may be plain or typed: A plain literal is a string combined with an optional language tag. It is considered to denote itself, so has a fixed meaning. A typed literal is [...]

Problems of the RDF model: Blank Nodes

There is a number of challenges regarding the realization of the Semantic Web vision.  In the series of blog posts to follow, I’ll be focusing on the Linked Data field and the ideas, technologies and standards it’s based on.  I’ll analyze the problems of the three important aspects of Linked Data:  the RDF model, the [...]