Keyphrases
- test collection
- information retrieval
- search tasks
- question answering
- retrieval effectiveness
- ad hoc retrieval
- neural network
- biomedical information retrieval
- pseudo relevance feedback
- relevance feedback
- social networks
- query performance prediction
- retrieval systems
- average precision
- probabilistic model
- clustering algorithm
- ir evaluation
- data sets
- trec blog track
- blog opinion retrieval