Keyphrases
- information retrieval
- grand challenges
- grand challenge
- information retrieval systems
- search engine
- language model
- technology enhanced learning
- information extraction
- text mining
- question answering
- document retrieval
- test collection
- boolean queries
- vector space model
- language modeling
- learning to rank
- retrieval effectiveness
- relevant documents
- document collections
- retrieval model
- neural network
- text categorization
- query expansion
- web search
- mid term