# fieldNorm & queryNorm in explain api **URL:** \ **Category:** Elasticsearch\ **Created:** [February 12, 2014, 5:32am UTC](https://discuss.elastic.co/t/fieldnorm-querynorm-in-explain-api/15747 "2014-02-12T05:32:43Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![usha2626](https://avatars.discourse-cdn.com/v4/letter/u/4bbf92/32.png) [@usha2626](https://discuss.elastic.co/u/usha2626)\ **Post date:** [February 12, 2014, 5:32am UTC](https://discuss.elastic.co/t/fieldnorm-querynorm-in-explain-api/15747/1 "2014-02-12T05:32:43Z")
Hi, I want to know what are fieldNorm and queryNorm in the output displayed by the explain api..how are they calculated? Thanks Usha -- You received this message because you are subscribed to the Google Groups "elasticsearch" group. To unsubscribe from this group and stop receiving emails from it, send an email to [elasticsearch+unsubscribe@googlegroups.com](mailto:elasticsearch+unsubscribe@googlegroups.com). To view this discussion on the web visit [https://groups.google.com/d/msgid/elasticsearch/a009d8bd-6646-492e-8dc0-1af682a78286%40googlegroups.com](https://groups.google.com/d/msgid/elasticsearch/a009d8bd-6646-492e-8dc0-1af682a78286%40googlegroups.com). For more options, visit [https://groups.google.com/groups/opt\_out](https://groups.google.com/groups/opt_out). ---
**Author:** ![Ivan](https://avatars.discourse-cdn.com/v4/letter/i/df788c/32.png) [@Ivan](https://discuss.elastic.co/u/Ivan)\ **Post date:** [February 12, 2014, 6:30am UTC](https://discuss.elastic.co/t/fieldnorm-querynorm-in-explain-api/15747/2 "2014-02-12T06:30:03Z")
The norms are calculated by Lucene's TFIDF algorithm: [http://lucene.apache.org/core/4\_6\_0/core/org/apache/lucene/search/similarities/TFIDFSimilarity.html](http://lucene.apache.org/core/4_6_0/core/org/apache/lucene/search/similarities/TFIDFSimilarity.html) The field norm is encoded into a single byte, so there is a loss of precision. -- Ivan On Tue, Feb 11, 2014 at 9:32 PM, [usha2626@gmail.com](mailto:usha2626@gmail.com) wrote: > Hi, > > I want to know what are fieldNorm and queryNorm in the output displayed by > the explain api..how are they calculated? > > Thanks > Usha > > -- > You received this message because you are subscribed to the Google Groups > "elasticsearch" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [elasticsearch+unsubscribe@googlegroups.com](mailto:elasticsearch+unsubscribe@googlegroups.com). > To view this discussion on the web visit > [https://groups.google.com/d/msgid/elasticsearch/a009d8bd-6646-492e-8dc0-1af682a78286%40googlegroups.com](https://groups.google.com/d/msgid/elasticsearch/a009d8bd-6646-492e-8dc0-1af682a78286%40googlegroups.com) > . > For more options, visit [https://groups.google.com/groups/opt\_out](https://groups.google.com/groups/opt_out). -- You received this message because you are subscribed to the Google Groups "elasticsearch" group. To unsubscribe from this group and stop receiving emails from it, send an email to [elasticsearch+unsubscribe@googlegroups.com](mailto:elasticsearch+unsubscribe@googlegroups.com). To view this discussion on the web visit [https://groups.google.com/d/msgid/elasticsearch/CALY%3DcQAzhPuEZ9H%2BN0pnC-xmWvscxitDie4%3DSVtjus\_B%2Bp8GDA%40mail.gmail.com](https://groups.google.com/d/msgid/elasticsearch/CALY%3DcQAzhPuEZ9H%2BN0pnC-xmWvscxitDie4%3DSVtjus_B%2Bp8GDA%40mail.gmail.com). For more options, visit [https://groups.google.com/groups/opt\_out](https://groups.google.com/groups/opt_out). ---
**Author:** ![Navneet\_Mathpal](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/navneet_mathpal/32/3677_2.png) [@Navneet\_Mathpal](https://discuss.elastic.co/u/Navneet_Mathpal)\ **Post date:** [February 12, 2014, 7:56am UTC](https://discuss.elastic.co/t/fieldnorm-querynorm-in-explain-api/15747/3 "2014-02-12T07:56:56Z")
Ivan formula is queryNorm(q) = queryNorm(sumOfSquaredWeights)[http://lucene.apache.org/core/4\_6\_0/core/org/apache/lucene/search/similarities/DefaultSimilarity.html#queryNorm(float)](http://lucene.apache.org/core/4_6_0/core/org/apache/lucene/search/similarities/DefaultSimilarity.html#queryNorm%28float%29) = 1 –––––––––––––– sumOfSquaredWeights½ The sum of squared weights (of the query terms) is computed by the query Weight[http://lucene.apache.org/core/4\_6\_0/core/org/apache/lucene/search/Weight.html](http://lucene.apache.org/core/4_6_0/core/org/apache/lucene/search/Weight.html)object. For example, a BooleanQuery[http://lucene.apache.org/core/4\_6\_0/core/org/apache/lucene/search/BooleanQuery.html](http://lucene.apache.org/core/4_6_0/core/org/apache/lucene/search/BooleanQuery.html)computes this value as: sumOfSquaredWeights[http://lucene.apache.org/core/4\_6\_0/core/org/apache/lucene/search/Weight.html#getValueForNormalization()](http://lucene.apache.org/core/4_6_0/core/org/apache/lucene/search/Weight.html#getValueForNormalization%28%29) = q.getBoost()[http://lucene.apache.org/core/4\_6\_0/core/org/apache/lucene/search/Query.html#getBoost()](http://lucene.apache.org/core/4_6_0/core/org/apache/lucene/search/Query.html#getBoost%28%29) 2 · ∑ ( idf(t)[http://lucene.apache.org/core/4\_6\_0/core/org/apache/lucene/search/similarities/TFIDFSimilarity.html#formula\_idf](http://lucene.apache.org/core/4_6_0/core/org/apache/lucene/search/similarities/TFIDFSimilarity.html#formula_idf) · t.getBoost()[http://lucene.apache.org/core/4\_6\_0/core/org/apache/lucene/search/similarities/TFIDFSimilarity.html#formula\_termBoost](http://lucene.apache.org/core/4_6_0/core/org/apache/lucene/search/similarities/TFIDFSimilarity.html#formula_termBoost) ) 2 t in q for my following search result how it is calculating: { - took: 16 - timed\_out: false - \_shards: { - total: 5 - successful: 5 - failed: 0 } - hits: { - total: 2 - max\_score: 0.2712221 - hits: [ - { - \_shard: 3 - \_node: k8BXmkARRsaaYlUJTRpIqQ - \_index: phone - \_type: iphone - \_id: 2 - \_score: 0.2712221 - \_source: { - title: iphone update - description: this section shows how to update yopur iphone to work smoothly in your iphone } - \_explanation: { - value: 0.27122214 - description: max of: - details: [ - { - value: 0.27122214 - description: sum of: - details: [ - { - value: 0.13561107 - description: weight(title:iphone in 0) [PerFieldSimilarity], result of: - details: [ - { - value: 0.13561107 - description: score(doc=0,freq=1.0 = termFreq=1.0 ), product of: - details: [ - { - value: 0.70710677 - description: queryWeight, product of: - details: [ - { - value: 0.30685282 - description: idf(docFreq=1, maxDocs=1) } - { - value: 2.3043842 - description: queryNorm } ] } - { - value: 0.19178301 - description: fieldWeight in 0, product of: - details: [ - { - value: 1 - description: tf(freq=1.0), with freq of: - details: [ - { - value: 1 - description: termFreq=1.0 } ] } - { - value: 0.30685282 - description: idf(docFreq=1, maxDocs=1) } - { - value: 0.625 - description: fieldNorm(doc=0) } ] } ] } ] } - { - value: 0.13561107 - description: weight(title:update in 0) [PerFieldSimilarity], result of: - details: [ - { - value: 0.13561107 - description: score(doc=0,freq=1.0 = termFreq=1.0 ), product of: - details: [ - { - value: 0.70710677 - description: queryWeight, product of: - details: [ - { - value: 0.30685282 - description: idf(docFreq=1, maxDocs=1) } - { - value: 2.3043842 - description: queryNorm } ] } - { - value: 0.19178301 - description: fieldWeight in 0, product of: - details: [ - { - value: 1 - description: tf(freq=1.0), with freq of: - details: [ - { - value: 1 - description: termFreq=1.0 } ] } - { - value: 0.30685282 - description: idf(docFreq=1, maxDocs=1) } - { - value: 0.625 - description: fieldNorm(doc=0) } ] } ] } ] } ] } - { - value: 0.16369703 - description: sum of: - details: [ - { - value: 0.0958915 - description: weight(description:iphone in 0) [PerFieldSimilarity], result of: - details: [ - { - value: 0.0958915 - description: score(doc=0,freq=2.0 = termFreq=2.0 ), product of: - details: [ - { - value: 0.70710677 - description: queryWeight, product of: - details: [ - { - value: 0.30685282 - description: idf(docFreq=1, maxDocs=1) } - { - value: 2.3043842 - description: queryNorm } ] } - { - value: 0.13561106 - description: fieldWeight in 0, product of: - details: [ - { - value: 1.4142135 - description: tf(freq=2.0), with freq of: - details: [ - { - value: 2 - description: termFreq=2.0 } ] } - { - value: 0.30685282 - description: idf(docFreq=1, maxDocs=1) } - { - value: 0.3125 - description: fieldNorm(doc=0) } ] } ] } ] } - { - value: 0.067805536 - description: weight(description:update in 0) [PerFieldSimilarity], result of: - details: [ - { - value: 0.067805536 - description: score(doc=0,freq=1.0 = termFreq=1.0 ), product of: - details: [ - { - value: 0.70710677 - description: queryWeight, product of: - details: [ - { - value: 0.30685282 - description: idf(docFreq=1, maxDocs=1) } - { - value: 2.3043842 - description: queryNorm } ] } - { - value: 0.095891505 - description: fieldWeight in 0, product of: - details: [ - { - value: 1 - description: tf(freq=1.0), with freq of: - details: [ - { - value: 1 - description: termFreq=1.0 } ] } - { - value: 0.30685282 - description: idf(docFreq=1, maxDocs=1) } - { - value: 0.3125 - description: fieldNorm(doc=0) } ] } ] } ] } ] } ] } } - { - \_shard: 2 - \_node: k8BXmkARRsaaYlUJTRpIqQ - \_index: phone - \_type: iphone - \_id: 1 - \_score: 0.04500804 - \_source: { - title: iphone - description: welcome to iphone world } - \_explanation: { - value: 0.04500804 - description: max of: - details: [ - { - value: 0.04500804 - description: product of: - details: [ - { - value: 0.09001608 - description: sum of: - details: [ - { - value: 0.09001608 - description: weight(title:iphone in 0) [PerFieldSimilarity], result of: - details: [ - { - value: 0.09001608 - description: score(doc=0,freq=1.0 = termFreq=1.0 ), product of: - details: [ - { - value: 0.29335263 - description: queryWeight, product of: - details: [ - { - value: 0.30685282 - description: idf(docFreq=1, maxDocs=1) } - { - value: 0.9560043 - description: queryNorm } ] } - { - value: 0.30685282 - description: fieldWeight in 0, product of: - details: [ - { - value: 1 - description: tf(freq=1.0), with freq of: - details: [ - { - value: 1 - description: termFreq=1.0 } ] } - { - value: 0.30685282 - description: idf(docFreq=1, maxDocs=1) } - { - value: 1 - description: fieldNorm(doc=0) } ] } ] } ] } ] } - { - value: 0.5 - description: coord(1/2) } ] } - { - value: 0.02250402 - description: product of: - details: [ - { - value: 0.04500804 - description: sum of: - details: [ - { - value: 0.04500804 - description: weight(description:iphone in 0) [PerFieldSimilarity], result of: - details: [ - { - value: 0.04500804 - description: score(doc=0,freq=1.0 = termFreq=1.0 ), product of: - details: [ - { - value: 0.29335263 - description: queryWeight, product of: - details: [ - { - value: 0.30685282 - description: idf(docFreq=1, maxDocs=1) } - { - value: 0.9560043 - description: queryNorm } ] } - { - value: 0.15342641 - description: fieldWeight in 0, product of: - details: [ - { - value: 1 - description: tf(freq=1.0), with freq of: - details: [ - { - value: 1 - description: termFreq=1.0 } ] } - { - value: 0.30685282 - description: idf(docFreq=1, maxDocs=1) } - { - value: 0.5 - description: fieldNorm(doc=0) } ] } ] } ] } ] } - { - value: 0.5 - description: coord(1/2) } ] } ] } } ] } } On Wednesday, 12 February 2014 12:00:03 UTC+5:30, Ivan Brusic wrote: > The norms are calculated by Lucene's TFIDF algorithm: > [TFIDFSimilarity (Lucene 4.6.0 API)](http://lucene.apache.org/core/4_6_0/core/org/apache/lucene/search/similarities/TFIDFSimilarity.html) > > The field norm is encoded into a single byte, so there is a loss of > precision. > > -- > Ivan > > On Tue, Feb 11, 2014 at 9:32 PM, \<[usha...@gmail.com](mailto:usha...@gmail.com) \\> wrote: > > > Hi, > > > > I want to know what are fieldNorm and queryNorm in the output displayed > > by the explain api..how are they calculated? > > > > Thanks > > Usha > > > > -- > > You received this message because you are subscribed to the Google Groups > > "elasticsearch" group. > > To unsubscribe from this group and stop receiving emails from it, send an > > email to [elasticsearc...@googlegroups.com](mailto:elasticsearc...@googlegroups.com) \. > > To view this discussion on the web visit > > [https://groups.google.com/d/msgid/elasticsearch/a009d8bd-6646-492e-8dc0-1af682a78286%40googlegroups.com](https://groups.google.com/d/msgid/elasticsearch/a009d8bd-6646-492e-8dc0-1af682a78286%40googlegroups.com) > > . > > For more options, visit [https://groups.google.com/groups/opt\_out](https://groups.google.com/groups/opt_out). -- You received this message because you are subscribed to the Google Groups "elasticsearch" group. To unsubscribe from this group and stop receiving emails from it, send an email to [elasticsearch+unsubscribe@googlegroups.com](mailto:elasticsearch+unsubscribe@googlegroups.com). To view this discussion on the web visit [https://groups.google.com/d/msgid/elasticsearch/4d86972e-6cca-488f-97d2-e9a1edef752f%40googlegroups.com](https://groups.google.com/d/msgid/elasticsearch/4d86972e-6cca-488f-97d2-e9a1edef752f%40googlegroups.com). For more options, visit [https://groups.google.com/groups/opt\_out](https://groups.google.com/groups/opt_out). ---
**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\ **Post date:** [July 6, 2017, 1:50am UTC](https://discuss.elastic.co/t/fieldnorm-querynorm-in-explain-api/15747/4 "2017-07-06T01:50:49Z")