2,155 research outputs found
A Vertical PRF Architecture for Microblog Search
In microblog retrieval, query expansion can be essential to obtain good
search results due to the short size of queries and posts. Since information in
microblogs is highly dynamic, an up-to-date index coupled with pseudo-relevance
feedback (PRF) with an external corpus has a higher chance of retrieving more
relevant documents and improving ranking. In this paper, we focus on the
research question:how can we reduce the query expansion computational cost
while maintaining the same retrieval precision as standard PRF? Therefore, we
propose to accelerate the query expansion step of pseudo-relevance feedback.
The hypothesis is that using an expansion corpus organized into verticals for
expanding the query, will lead to a more efficient query expansion process and
improved retrieval effectiveness. Thus, the proposed query expansion method
uses a distributed search architecture and resource selection algorithms to
provide an efficient query expansion process. Experiments on the TREC Microblog
datasets show that the proposed approach can match or outperform standard PRF
in MAP and NDCG@30, with a computational cost that is three orders of magnitude
lower.Comment: To appear in ICTIR 201
Modeling Temporal Evidence from External Collections
Newsworthy events are broadcast through multiple mediums and prompt the
crowds to produce comments on social media. In this paper, we propose to
leverage on this behavioral dynamics to estimate the most relevant time periods
for an event (i.e., query). Recent advances have shown how to improve the
estimation of the temporal relevance of such topics. In this approach, we build
on two major novelties. First, we mine temporal evidences from hundreds of
external sources into topic-based external collections to improve the
robustness of the detection of relevant time periods. Second, we propose a
formal retrieval model that generalizes the use of the temporal dimension
across different aspects of the retrieval process. In particular, we show that
temporal evidence of external collections can be used to (i) infer a topic's
temporal relevance, (ii) select the query expansion terms, and (iii) re-rank
the final results for improved precision. Experiments with TREC Microblog
collections show that the proposed time-aware retrieval model makes an
effective and extensive use of the temporal dimension to improve search results
over the most recent temporal models. Interestingly, we observe a strong
correlation between precision and the temporal distribution of retrieved and
relevant documents.Comment: To appear in WSDM 201
DutchHatTrick: semantic query modeling, ConText, section detection, and match score maximization
This report discusses the collaborative work of the ErasmusMC, University of Twente, and the University of Amsterdam on the TREC 2011 Medical track. Here, the task is to retrieve patient visits from the University of Pittsburgh NLP Repository for 35 topics. The repository consists of 101,711 patient reports, and a patient visit was recorded in one or more reports
Knowledge-based Query Expansion in Real-Time Microblog Search
Since the length of microblog texts, such as tweets, is strictly limited to
140 characters, traditional Information Retrieval techniques suffer from the
vocabulary mismatch problem severely and cannot yield good performance in the
context of microblogosphere. To address this critical challenge, in this paper,
we propose a new language modeling approach for microblog retrieval by
inferring various types of context information. In particular, we expand the
query using knowledge terms derived from Freebase so that the expanded one can
better reflect users' search intent. Besides, in order to further satisfy
users' real-time information need, we incorporate temporal evidences into the
expansion method, which can boost recent tweets in the retrieval results with
respect to a given topic. Experimental results on two official TREC Twitter
corpora demonstrate the significant superiority of our approach over baseline
methods.Comment: 9 pages, 9 figure
Concept-based Interactive Query Expansion Support Tool (CIQUEST)
This report describes a three-year project (2000-03) undertaken in the Information Studies
Department at The University of Sheffield and funded by Resource, The Council for
Museums, Archives and Libraries. The overall aim of the research was to provide user
support for query formulation and reformulation in searching large-scale textual resources
including those of the World Wide Web. More specifically the objectives were: to investigate
and evaluate methods for the automatic generation and organisation of concepts derived from
retrieved document sets, based on statistical methods for term weighting; and to conduct
user-based evaluations on the understanding, presentation and retrieval effectiveness of
concept structures in selecting candidate terms for interactive query expansion.
The TREC test collection formed the basis for the seven evaluative experiments conducted in
the course of the project. These formed four distinct phases in the project plan. In the first
phase, a series of experiments was conducted to investigate further techniques for concept
derivation and hierarchical organisation and structure. The second phase was concerned with
user-based validation of the concept structures. Results of phases 1 and 2 informed on the
design of the test system and the user interface was developed in phase 3. The final phase
entailed a user-based summative evaluation of the CiQuest system.
The main findings demonstrate that concept hierarchies can effectively be generated from
sets of retrieved documents and displayed to searchers in a meaningful way. The approach
provides the searcher with an overview of the contents of the retrieved documents, which in
turn facilitates the viewing of documents and selection of the most relevant ones. Concept
hierarchies are a good source of terms for query expansion and can improve precision. The
extraction of descriptive phrases as an alternative source of terms was also effective. With
respect to presentation, cascading menus were easy to browse for selecting terms and for
viewing documents. In conclusion the project dissemination programme and future work are
outlined
Query Expansion with Locally-Trained Word Embeddings
Continuous space word embeddings have received a great deal of attention in
the natural language processing and machine learning communities for their
ability to model term similarity and other relationships. We study the use of
term relatedness in the context of query expansion for ad hoc information
retrieval. We demonstrate that word embeddings such as word2vec and GloVe, when
trained globally, underperform corpus and query specific embeddings for
retrieval tasks. These results suggest that other tasks benefiting from global
embeddings may also benefit from local embeddings
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