Cultivating trees: adding several semantic layers to the Lassy treebank in SoNaR

Within the STEVIN1 project Large Scale Syntactic Annotation of written Dutch (LASSY), a manually corrected treebank of 1 million words is constructed. Lassy is part of a series of annotation projects for modern written and spoken Dutch. More specifically, it is an extension of the D-Coi and CGN projects,2 and constitutes the core of SoNaR, a 500 million words reference corpus of modern written Dutch.3 One of the goals of the latter project is to enrich the corrected treebank produced in Lassy4 with several semantic layers. For a general overview of the relations between D-Coi, Lassy and SoNaR, cf [19]. In this paper we will concentrate on the semantic layers of SoNaR core: (1) named entity labeling, (2) annotation of co-reference relations, (3) semantic role labeling and (4) annotation of spatial and temporal relations. Of these (2) originates from the STEVIN-project COREA,5 (3) and (4) from D-Coi, whereas (1) is a new area within STEVIN.