tailieunhanh - Báo cáo khoa học: "Classification of Semantic Relationships between Nominals Using Pattern Clusters"

There are many possible different semantic relationships between nominals. Classification of such relationships is an important and difficult task (for example, the well known noun compound classification task is a special case of this problem). We propose a novel pattern clusters method for nominal relationship (NR) classification. Pattern clusters are discovered in a large corpus independently of any particular training set, in an unsupervised manner. Each of the extracted clusters corresponds to some unspecified semantic relationship. . | Classification of Semantic Relationships between Nominals Using Pattern Clusters Dmitry Davidov ICNC Hebrew University of Jerusalem dmitry@ Ari Rappoport Institute of Computer Science Hebrew University of Jerusalem arir@ Abstract There are many possible different semantic relationships between nominals. Classification of such relationships is an important and difficult task for example the well known noun compound classification task is a special case of this problem . We propose a novel pattern clusters method for nominal relationship NR classification. Pattern clusters are discovered in a large corpus independently of any particular training set in an unsupervised manner. Each of the extracted clusters corresponds to some unspecified semantic relationship. The pattern clusters are then used to construct features for training and classification of specific inter-nominal relationships. Our NR classification evaluation strictly follows the ACL SemEval-07 Task 4 datasets and protocol obtaining an f-score of as opposed to of the best previous work that did not use the manually provided WordNet sense disambiguation tags. 1 Introduction Automatic extraction and classification of semantic relationships is a major field of activity of both practical and theoretical interest. A prominent type of semantic relationships is that holding between nominals1. For example in noun compounds many different semantic relationships are encoded by the same simple form Girju et al. 2005 dog food denotes food consumed by dogs while summer morn 1Our use of the term nominal follows Girju et al 2007 and includes simple nouns noun compounds and multiword expressions serving as nouns. ing denotes a morning t f i t happens in the summer. These two relationships are completely different semantically but are similar syntactically and distinguishing between them could be essential for NLP applications such as question answering and machine translation. .