University of Glasgow (UGLA-D) at TREC Microblog 2011: temporal pseudo-relevance feedback in microblog retrieval

This submission represents a first attempt to apply temporal pseudorelevance feedback for the microblog context. For our submission to the TREC Microblogging 2011 track we perform two approaches, which serve as our initial bases for retrieval. Our first approach uses the retrieval facilities of a standard MySQL server on a heuristically altered tweet collection. Our second approach intends to improve on this initial retrieval through pseudo-relevance feedback, based upon the temporal profiles of n-grams extracted from the top N relevance feedback tweets. A weighted graph is used to model temporal correlation between n-grams, with a PageRank variant employed to combine both pseudo-relevant document term distribution and temporal collection evidence. Preliminary experiments with the TREC Microblogging 2011 Twitter corpus indicate that through parameter optimisation, retrieval effectiveness can be improved