Compact query term selection using topically related text.
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Introduction
This paper illustrate a method called PhRank, selecting terms from retrieved documents by a query.The effects follows:
Methods
Graph construction Input:query Q = {w1,…wn}
N = {d0 , ….dk } ,Q+the top k documents retrieved
It considers three relationships between terms: co-occurrence, stemming and association.
Here is an example:
Edge weights p(dk|Q) : the probability of the document in which the stems i and j co-occur given Q cijW2 and cijW10: the counts of stem co-occurrence in windows of size 2 and 10inN λ is set to 0.6
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- Random Walk The probability hij = lij if vi and vj are connected, and hij = 0 otherwise. πjt be the affinity score associated with vj at time t.
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- Vertex weights wnfavg is the frequency of a word wn in N.
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- Term ranking
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Comparison
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The End!
Reference: K.Tamsin Maxwell, W.Bruce Croft:SIGIR 2013: 583-592.Compact query term selection using topically related text.