Package com.hrstc.lucene.queryexpansion

LucQE [lucky] - Lucene Query Expansion Module


Class Summary
GoogleSearcher Performs Query Expansion, utilizing google for document source
QueryExpansion Implements Rocchio's pseudo feedback QueryExpansion algorithm

Package com.hrstc.lucene.queryexpansion Description

LucQE [lucky] - Lucene Query Expansion Module

Provides a framework along with several implementations that allow to perform Query Expansion (QE) with the use of Apache Lucene.

Query Expansion - Adding search terms to a user's search. Query expansion is the process of a search
engine adding search terms to a user's weighted search. The intent is to improve precision and/or recall. The additional terms may be taken from a thesaurus. For example a search for "car" may be expanded to: car cars auto autos automobile automobiles [].

Following modules have been implemented:


Experiments were conducted on the data from TREC 2004 Robust Track.

Note: This data is provided for reference purposes only. Better performance on the specific data set may not necessary be repeated on the different data sets, etc...

Tag Combined Topic Set 
MAP P10 %no
Lucene gQE 0.2332 0.3984 14%
KB-R-FIS gQE 0.2322 0.4076 14%
Lucene 0.2 0.37 15%

MAP - mean average precision
P10 - average of precision at 10 documents retrieved
%no - percentage of topics with no relevant in the top 10 retrieved

Lucene - unmodified version 1.4.3
Lucene gQE – Lucene system that utilized Rocchio’s query expansion along with Google.
KB-R-FIS gQE – My Fuzzy Inference System that utilized Rocchio’s query expansion along with Google.


To see a demo of a project run 'demo' script at the root of the project.

Neil O. Rouben