For the calculation of norm, see note number 6:
http://lucene.apache.org/core/4_3_0/core/org/apache/lucene/search/similarities/TFIDFSimilarity.html
You would need to talk to the Nutch guys to see why THEY are setting
document boost to 0.0.
-- Jack Krupansky
-----Original Message-----
From: Joe Zhang
Sent: Friday, July 12, 2013 11:57 PM
To: solr-user@lucene.apache.org
Subject: Re: zero-valued retrieval scores
Yes, you are right, the boost on these documents are 0. I didn't provide
them, though.
I suppose the boost scores come from Nutch (yes, my solr indexes crawled
web docs). What could be wrong?
again, what exactly is the formula for fieldNorm?
On Fri, Jul 12, 2013 at 8:46 PM, Jack Krupansky
<j...@basetechnology.com>wrote:
Did you put a boost of 0.0 on the documents, as opposed to the default of
1.0?
x * 0.0 = 0.0
-- Jack Krupansky
-----Original Message----- From: Joe Zhang
Sent: Friday, July 12, 2013 10:31 PM
To: solr-user@lucene.apache.org
Subject: zero-valued retrieval scores
when I search a keyword (such as "apple"), most of the docs carry 0.0 as
score. Here is an example from explain:
str name="
http://www.bloomberg.com/**slideshow/2013-07-12/world-at-**work-india.html<http://www.bloomberg.com/slideshow/2013-07-12/world-at-work-india.html>
">
0.0 = (MATCH) fieldWeight(content:appl in 51), product of:
1.0 = tf(termFreq(content:appl)=1)
2.096877 = idf(docFreq=5190, maxDocs=15546)
0.0 = fieldNorm(field=content, doc=51)
Can somebody help me understand why fieldNorm is 0? What exactly is the
formula for computing fieldNorm?
Thanks!
