Keyphrases
- question answering
- information retrieval
- information extraction
- natural language processing
- natural language
- cross language
- question classification
- syntactic information
- named entities
- question answering systems
- passage retrieval
- relation extraction
- open domain question answering
- machine learning
- sentence retrieval
- machine translation
- semantic roles
- web search engines
- web search
- qa clef
- answering questions
- answer validation
- data mining