In this paper we give a brief overview of the Webis group’s participation in the TREC 2011 Sessions track with an extended version of our last year’s approach [HSV10]. The basic idea can be described as a conservative query expansion based on terms used in previous queries or terms contained in clicked snippets. Furthermore, a query’s result set is reduced by removing documents shown for previo...

We report our system and experiments for the realtime Adhoc task in the 2011 MicroBlog track. Our goal is to develop effective technique to retrieve relevant tweets that have been posted recently. In particular, we propose a time-­sensitive term weighting strategy that can favor tweets in hot-­discussed time and a document length related weighting method that can favor long tweets which are mor...

This paper details Cengage Learning’s submissions for this year’s TREC medical track. The techniques we used fall roughly into two categories: information extraction and query expansion. From both the queries and the medical reports, we extracted limiting attributes, such as age, race, and gender, and labeled terms appearing in the Unified Medical Language System (UMLS). We also used three diff...

Query expansion is a well known method to improve the performance of information retrieval systems. In this work we have tested different approaches to extract the candidate query terms from the top ranked documents returned by the first-pass retrieval. One of them is the cooccurrence approach, based on measures of cooccurrence of the candidate and the query terms in the retrieved documents. Th...

In this report we discuss the experiments we conducted at the University of Wolverhampton for the Microblog Track at TREC-2011. As this was the first time we participated in TREC and the particular task presents some unique challenges we initially focused on properly analyzing and indexing the new Tweets2011 Corpus. We experimented with the effects that some standard IR techniques, such as quer...

This paper describes our participation in the Medical Retrieval task at ImageCLEF 2008. We present the joint work of two teams belonging to the TEXT-MESS project using a new system that combines the 2 individual systems of these teams. The aim of the experiments performed is to figure out if there are techniques used in one of the two systems which can complement the other system in order to im...

The appearance of microblogging services has led to many short documents being issued by crowds of people. To retrieve useful information from among such a huge quantity of messages, query expansion (QE) is usually used to enrich a user query. Some QE methods for microblog search utilize temporal properties (e.g., recency and temporal variation) derived from the real-time characteristic that ma...