Keyphrases
- query expansion
- retrieval effectiveness
- information retrieval systems
- language model
- text retrieval
- relevance feedback
- information retrieval
- pseudo relevance feedback
- social web
- relevant documents
- retrieval model
- original query
- ad hoc retrieval
- language modeling
- improving search
- social tagging
- query expansion methods
- query terms
- retrieved documents
- query disambiguation
- biomedical information retrieval
- automatic query expansion
- probabilistic model
- pseudo feedback