Keyphrases
- topic detection and tracking
- information retrieval
- test collection
- retrieval effectiveness
- question answering
- news articles
- news stories
- keywords
- hot topics
- social media
- online news
- pseudo relevance feedback
- data sets
- ad hoc retrieval
- expert search
- query expansion
- website
- search tasks
- relevance judgements
- search engine
- ir evaluation
- news topics