2,303 research outputs found
Semantic Query Reformulation in Social PDMS
We consider social peer-to-peer data management systems (PDMS), where each
peer maintains both semantic mappings between its schema and some
acquaintances, and social links with peer friends. In this context,
reformulating a query from a peer's schema into other peer's schemas is a hard
problem, as it may generate as many rewritings as the set of mappings from that
peer to the outside and transitively on, by eventually traversing the entire
network. However, not all the obtained rewritings are relevant to a given
query. In this paper, we address this problem by inspecting semantic mappings
and social links to find only relevant rewritings. We propose a new notion of
'relevance' of a query with respect to a mapping, and, based on this notion, a
new semantic query reformulation approach for social PDMS, which achieves great
accuracy and flexibility. To find rapidly the most interesting mappings, we
combine several techniques: (i) social links are expressed as FOAF (Friend of a
Friend) links to characterize peer's friendship and compact mapping summaries
are used to obtain mapping descriptions; (ii) local semantic views are special
views that contain information about external mappings; and (iii) gossiping
techniques improve the search of relevant mappings. Our experimental
evaluation, based on a prototype on top of PeerSim and a simulated network
demonstrate that our solution yields greater recall, compared to traditional
query translation approaches proposed in the literature.Comment: 29 pages, 8 figures, query rewriting in PDM
Same query - different results? A study of repeat queries in search sessions
Typically, three main query reformulation types in sessions
are considered: generalization, specication, and drift. We show that given the full context of user interactions, repeat queries represent an important reformulation type which should also be addressed in session retrieval evaluation. We investigate dierent query reformulation patterns in logs from The European Library. Using an automatic classification for query reformulations, we found that the most frequent (and presumably the most important) reformulation pattern corresponds to repeat queries. We aim to nd possible explanations for repeat queries in sessions and try to uncover implications for session retrieval evaluation
Task-Oriented Query Reformulation with Reinforcement Learning
Search engines play an important role in our everyday lives by assisting us
in finding the information we need. When we input a complex query, however,
results are often far from satisfactory. In this work, we introduce a query
reformulation system based on a neural network that rewrites a query to
maximize the number of relevant documents returned. We train this neural
network with reinforcement learning. The actions correspond to selecting terms
to build a reformulated query, and the reward is the document recall. We
evaluate our approach on three datasets against strong baselines and show a
relative improvement of 5-20% in terms of recall. Furthermore, we present a
simple method to estimate a conservative upper-bound performance of a model in
a particular environment and verify that there is still large room for
improvements.Comment: EMNLP 201
Query Reformulation for Indonesian Question Answering System Using Word Embedding of Word2Vec
Query reformulation is one of the tasks in Information Retrieval (IR), which automatically creates new queries based on previous queries. The main challenge of query reformulation is to create a new query whose meaning or context is similar to the old query. Query reformulation can improve the search for relevant documents for Open-domain Question Answering (OpenQA). The more queries are given to the search system, and the more documents will be generated. We propose a Word Predicted and Substituted (WPS) method for query reformulation using a word embedding word2vec. We tested this method on the Indonesian Question Answering System (IQAS). The test results obtained an E-1 value of 81% and an E-2 value of 274%. These results prove that the query reformulation method with WPS and word-embedding can improve the search for potential IQAS answers
External query reformulation for text-based image retrieval
In text-based image retrieval, the Incomplete Annotation
Problem (IAP) can greatly degrade retrieval effectiveness. A standard method used to address this problem is pseudo relevance feedback (PRF) which updates user queries by adding feedback terms selected automatically from top ranked documents in a prior retrieval run. PRF assumes that the target collection provides enough feedback information to select effective expansion terms. This is often not the case in image retrieval since images often only have short metadata annotations leading to the IAP. Our work proposes the use of an external knowledge resource (Wikipedia) in the process of refining user queries. In our method, Wikipedia documents strongly related to the terms in user query ("
definition documents") are first identified by title matching between the query and titles of Wikipedia articles. These definition documents are used as indicators to re-weight the feedback documents from an initial search
run on a Wikipedia abstract collection using the Jaccard coefficient. The new weights of the feedback documents are combined with the scores rated by different indicators. Query-expansion terms are then selected based on these new weights for the feedback documents. Our method is evaluated on the ImageCLEF WikipediaMM image retrieval task using text-based retrieval on the document metadata fields. The results show significant improvement compared to standard PRF methods
Query reformulation with constraints
Let Σ1, Σ2 be two schemas, which may overlap, C be a set of constraints on the joint schema Σ1 ∪ Σ2, and q1 be a Σ1-query. An (equivalent) reformulation of q1 in the presence of C is a Σ2-query, q2, such that q2 gives the same answers as q1 on any Σ1 ∪ Σ2-database instance that satisfies C. In general, there may exist multiple such reformulations and choosing among them may require, for example, a cost model
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