Hi Madhu,

>1. What is the search algorithm(s)[VSM, ..] used or available in the

Lucene?

Lucene uses Vector Space Model as its retrieval model.

>2 How term weight is calculated in Lucene, how many types of term

weight calculating formulas are implemented and what are they?

TF-IDF weighting is used with some modifications to how the raw score is

computed. You can refer to "Lucene In Action" by Otis Gospodnetic and

Erik Hatcher" page 78. Here is the formula

= SUMMATION {tf(t in d).idf(t).boost(t.field in d). lengthNorm(t.field

in d)

t in q

There are variations in how you can compute this score. For example

by setting different boost level while indexing or searching. But the

basic scoring is still based on TF-IDF weighting.

Hope it helps.

Rajesh Munavalli

-----Original Message-----

From: Madhu Panitini [mailto:

[hidden email]]

Sent: Monday, August 08, 2005 12:02 PM

To:

[hidden email]
Subject: search alogorithm in Lucene

Hi all,

I new to the lucene, but I am familiar with the IR. I want build IR

system in Java and I found Lucene, but some questions remained

unanswered for me after searching complete website.

I have couple of questions regarding Lucene,

1. What is the search algorithm(s)[VSM, ..] used or available in the

Lucene?

2. How term weight is calculated in Lucene, how many types of term

weight calculating formulas are implemented and what are they?

Regards

Madhu