Derry Wijaya: Building Lexical Resources for NLP

Derry Wijaya: Building Lexical Resources for NLP

Abstract:
One of the ways we can formulate natural language understanding is by treating it as a task of mapping natural language text to its meaning representation: entities and relations anchored to the world. Since verbs express relations over their arguments and adjuncts, a lexical resource about verbs can facilitate natural language understanding by mapping verbs to relations over entities expressed by their arguments and adjuncts in the world. In my thesis work, I semi-automatically construct a large scale verb resource called VerbKB that contains some of these mappings for natural language understanding. A verb lexical unit in VerbKB consists of a verb lexeme or a verb lexeme and a preposition e.g., “live”, “live in”, which is typed with a pair of NELL knowledge base semantic categories that indicates its subject type and its object type e.g., “live in”(person, location). In this talk, I will present the algorithms behind VerbKB that will complement existing resources of verbs such as WordNet and VerbNet and existing knowledge bases about entities such as NELL. VerbKB contains two types of mappings: (1) the mappings from verb lexical units to binary relations in knowledge bases (e.g., the mapping from the verb lexical unit “die at”(person, nonNegInteger) to the binary relation personDiedAtAge) and (2) the mappings from verb lexical units to changes in binary relations in knowledge bases (e.g., the mapping from the verb lexical unit “divorce”(person, person) to the termination of the relation hasSpouse). I will present algorithms for these two mappings and how we extend VerbKB to cover relations beyond existing relations in NELL knowledge base. In the spirit of building multilingual lexical resources for NLP, I will also briefly discuss my recent work in building lexical translations for high-resource and low-resource languages from monolingual or comparable corpora.