Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: QA4PRF: A Question Answering based Framework for Pseudo Relevance
  Feedback   Pseudo relevance feedback (PRF) automatically performs query expansion based
on top-retrieved documents to better represent the user's information need so
as to improve the search results. Previous PRF methods mainly select expansion
terms with high occurrence frequency in top-retrieved documents or with high
semantic similarity with the original query. However, existing PRF methods
hardly try to understand the content of documents, which is very important in
performing effective query expansion to reveal the user's information need. In
this paper, we propose a QA-based framework for PRF called QA4PRF to utilize
contextual information in documents. In such a framework, we formulate PRF as a
QA task, where the query and each top-retrieved document play the roles of
question and context in the corresponding QA system, while the objective is to
find some proper terms to expand the original query by utilizing contextual
information, which are similar answers in QA task. Besides, an attention-based
pointer network is built on understanding the content of top-retrieved
documents and selecting the terms to represent the original query better. We
also show that incorporating the traditional supervised learning methods, such
as LambdaRank, to integrate PRF information will further improve the
performance of QA4PRF. Extensive experiments on three real-world datasets
demonstrate that QA4PRF significantly outperforms the state-of-the-art methods.

3
The categories of this paper are: physics
11
The categories of this paper are: hep-lat
6
The categories of this paper are: astro-ph
8
The categories of this paper are: hep-ex
19
The categories of this paper are: eess
2
The categories of this paper are: math
31
The categories of this paper are: ao-sci
7
The categories of this paper are: hep-th
25
The categories of this paper are: patt-sol
20
The categories of this paper are: acc-phys
26
The categories of this paper are: bayes-an
37
The categories of this paper are: supr-con
10
The categories of this paper are: q-bio
9
The categories of this paper are: nlin
34
The categories of this paper are: chem-ph
4
The categories of this paper are: cond-mat