1Controlled English for Reasoning on the Semantic Web

Abstract. The existing Semantic Web languages have a very technical focus and fail to provide good usability for users with no background in formal methods. We argue that controlled natural languages like At-tempto Controlled English (ACE) can solve this problem. ACE is a sub-set of English that can be translated into various logic based languages, among them the Semantic Web standards OWL and SWRL. ACE is accompanied by a set of tools, namely the parser APE, the Attempto Reasoner RACE, the ACE View ontology and rule editor, the semantic wiki AceWiki, and the Protune policy framework. The applications cover a wide range of Semantic Web scenarios, which shows how broadly ACE can be applied. We conclude that controlled natural languages can make the Semantic Web better understandable and more usable. 1.1 Why Use Controlled Natural Languages for the Semantic Web? The Semantic Web proves to be quite challenging for its developers: there is the problem of adequately representing domain knowledge, there is the question of the interoperability of heterogeneous knowledge bases, there is the need for reliable and efficient reasoning, and last but not least the Semantic Web requires generally acceptable user interfaces. Languages like RDF, OWL, SWRL, RuleML, R2ML, SPARQL etc. have been developed to meet the challenges of the Semantic Web. The developers of these languages are predominantly researchers with a strong background in logic. This is reflected in the languages, all of which have syntaxes that conspicuously show their logic descent. Domain experts and end-users, however, often do not have a background in logic. They shy away from logic notations, and prefer to use notations familiar to them — which is usually natural language possibly complemented by diagrams, tables, and formulas