Unsupervised and Open Ontology-Based Semantic Analysis

This paper presents an unsupervised and domain independent semantic analysis that outputs two types of formal representations: discourse representations structures and flat scope-free logical forms. This semantic analysis is built on top of dependency relations produced by a statistical syntactic parser, and is generated by a grammar of patterns named α-grammar. The interest of this grammar lies in building a clear linguistically-grounded syntax-semantic interface using a representation (dependencies) commonly used in the natural language processing community. The paper also explains how semantic representations can be annotated using an upper-level ontology, thus enabling further inference capabilities. The evaluation of the α-Grammar on a hand-made gold standard and on texts from the STEP 2008 Shared Task competition shows the interest of the approach.