Detecting Relational Constructions in German Texts Automatically

Lobner’s theory of concept types and determination (CTD) claims that nouns show different distributional fingerprints depending on their lexical determination class. In order to investigate this hypothesis, corpora annotated by determination patterns are needed (definiteness and relationality). In the paper, we focus on the harder of the two annotation tasks, the automatic detection of relational constructions. We apply a standard NLP pipeline and classification algorithms. Using a combination of symbolic and statistical approaches, we achieve a precision of 94.4% and a recall rate of 88.6% for the correct structural annotation of relational NPs. 1 Motivation and previous research The paper describes the design and the evaluation of a set of classifiers that identify relational constructions within complex German noun phrases. The classifiers are intended to detect possessive relational structures consisting of the two arguments ‘possessor’ (POSS) and ‘possessum’ (PUM) and to label these arguments correctly. Our work is embedded in a bigger research project that investigates Lobner’s theory of concept types and determination (CTD). According to Lobner, on the lexical level there are four basic noun types that differ with respect to two binary features, namely inherent uniqueness, ±U , and inherent relationality,±R (Lobner, 1985; Lobner, 2011). Inherently unique nouns describe a unique referent in a given context, e.g., ‘pope’, ‘Mary’ or ‘head [of]’ versus ‘tree’, ‘stone’ or ‘student [of]’. Inherently relational nouns are semantically unsaturated. They describe their referents by a relation to a possessor argument that must be found in their contexts of utterance, e.g., ‘trunk [of]’ or ‘sister [of]’ versus ‘tree’ or ‘woman’. With respect to the two binary features ±U and ±R four basic noun types can be distinguished (see table 1: Non-relational nouns are either sortal [−U,−R] or individual [+U,−R] while relational nouns are either functional [+U,+R] or proper relational [−U,+R]). 1 According to Lobner, each noun type is linked to a ‘natural’ mode of determination, its congruent determination: +U is linked to definiteness and +R to possessive determination. In case of congruent determination, sortal nouns occur in indefinite, absolute uses (‘a stone’, [Det−U , Det−R]), individual ones in singular definite, absolute uses (‘the pope’, [Det+U , Det−R]), proper relational ones in indefinite, relational uses (‘a sister of Mary’, [Det−U , Det+R]), and functional nouns in singular definite, relational uses (‘the head of Mary’, [Det+U , Det+R]). However, in concrete utterances nouns often appear in incongruent determination modes that use other determination types. Such incongruent uses trigger coercions or type shifts and increase the semantic complexity. For example, typical anaphoric uses of nouns involve a pragmatic shift from non-uniqueness to uniqueness as in ‘A woman entered the room. [. ] Mary knew the woman from school. ’ Other examples for type shifts are generic uses like ‘Mary acts like a pope’ or metaphorical shifts like ‘Mary bought a Picasso’. Many languages reflect the conceptual shifts grammatically and thus provide strong evidence for Lobner’s claim that the type of a noun is fixed in the lexicon.2 The classifiers described in For an early, independent distinction of functional and proper relational nouns along the same lines see de Bruin and Scha (1988). Languages with article split systems mark shifts ex-