QCRI at TREC 2014: Applying the KISS principle for the TTG task in the Microblog Track

In this paper we present our work on the ad-hoc search and the tweet timeline generation (TTG) tasks of TREC-2014 Microblog track. Regarding the ad-hoc search task, we used our best developed system over the last year, which include hyperlinkbased query expansion and re-ranking models fusion. For the new tweet timeline generation task, we applied a straightforward and simple approach, which depends on clustering retrieval results based on Jaccard similarities between tweets. Our best adhoc results achieved the fifth rank and seventh rank among 21 participating groups when evaluated using P@30 and MAP respectively. However, our best TTG run achieved the second rank among participants, which shows that our simple TTG approach was more effective than most of the used TTG systems in TREC.