Keyphrases
- question answering
- trec web
- test collection
- information retrieval
- search tasks
- natural language processing
- passage retrieval
- semantic roles
- information extraction
- cross language
- semantic parsing
- question classification
- natural language
- syntactic information
- qa clef
- relation extraction
- question answering systems
- named entities
- open domain question answering
- qa systems
- candidate answers
- answer extraction
- language model
- machine learning
- document collections
- knowledge representation