Pragmatic Semantics for the Web of Data

The Web of Data (WOD) is complex, and inherently messy, contextualised, opinionated, in short: it is a market-place of ideas, rather than a database. Logic-based semantics were not developed, and are not suitable, for such complex systems. A radically new approach to semantics is required. We introduce pragmatic semantics as a new semantic paradigm integrating elements from market-theory and classical semantics into a framework of optimisation over truth-orderings, each representing a particular world-view. We propose nature-based algorithms to implement those semantics. 1 Semantics for a Complex System 1 On the Web in general, and the Web of Data (WoD) in particular, almost every 2 piece of information is strongly context-dependent and described from multi3 ple viewpoints. The Web of Data is nowadays more and more recognised to be 4 a Complex System [4], with interlinked information at different scales of ab5 straction. A well-argued claim in the Complex Systems literature suggests that 6 it is impossible to construct logical systems that capture the full meaning of 7 any Complex System. Thus, approaches to extend current methods, for exam8 ple, with quantitative information about vagueness and uncertainty, or towards 9 multi-dimensionality (for modelling contexts), although highly useful and in10 genious for specific applications, necessarily fall short of representing the full 11 richness of semantics of the Web of Data. 12 This implies that the classical semantics of data and ontology languages such 13 as RDF(S) and OWL, which is based on truth with respect to all world-views (or 14 models) is often inappropriate, as those languages are not designed to deal with 15 inconsistent, multi-dimensional and contextualised knowledge. The most promis16 ing recent attempt to address this problem is the work on Emergent Semantics 17 [2], defining semantics as the result of collective processes and interactions be18 tween nodes in a network a collective agreement. Although this formalism can 19 capture some of the emerging structure, the price is that meaning and truth are 20 defined as results of processes or calculi, and the well-understood declarative, 21 model-theoretic semantics of traditional formalisms are lost. 22 Nevertheless, the Semantic Web requires semantics to allow for interoperabil23 ity and seamless interchange of data. In order to solve this apparent CATCH-22, 24 we propose a new semantic paradigm based on multi-objective optimisation of 25 a variety of truth criteria, which we will call Pragmatic Semantics. We will 26 finally argue that Pragmatic Semantics require nature-inspired calculi, such as 27 swarm or evolutionary algorithms. 28