Encoding syntactic dependencies using Random Indexing and Wikipedia as a corpus

Distributional approaches are based on a simple hypothesis: the meaning of a word can be inferred from its usage. The application of that idea to the vector space model makes possible the construction of a WordSpace in which words are represented by mathematical points in a geometric space. Similar words are represented close in this space and the definition of "word usage" depends on the definition of the context used to build the space, which can be the whole document, the sentence in which the word occurs, a fixed window of words, or a specific syntactic context. However, in its original formulation WordSpace can take into account only one definition of context at a time. We propose an approach based on vector permutation and Random Indexing to encode several syntactic contexts in a single WordSpace. We adopt WaCkypedia EN corpus to build our WordSpace that is a 2009 dump of the English Wikipedia (about 800 million tokens) annotated with syntactic information provided by a full dependency parser. The effectiveness of our approach is evaluated using the GEometrical Models of natural language Semantics (GEMS) 2011 Shared Evaluation data.