# Value of docFreq is wrong (using single shard)
**URL:** https://discuss.elastic.co/t/value-of-docfreq-is-wrong-using-single-shard/185846
**Category:** Elasticsearch
**Created:** [June 14, 2019, 11:59am UTC](https://discuss.elastic.co/t/value-of-docfreq-is-wrong-using-single-shard/185846 "2019-06-14T11:59:37Z")
**Posts on this page:** 3
**Page:** 1
### Author:  [@fsommer](https://discuss.elastic.co/u/fsommer)
#### Post date: [June 14, 2019, 11:59am UTC](https://discuss.elastic.co/t/value-of-docfreq-is-wrong-using-single-shard/185846/1 "2019-06-14T11:59:37Z")
Hello,
we are using Elasticsearch for a search application and are experiencing weird scoring behaviour. I used "explain: true" to understand the scoring and it seems to me that the "docFreq" (number of documents a term is included in) has a wrong value.
I reduced it to the following example (its german, but I think you can understand it nevertheless):
I'm adding two documents with the titles:
**"Bürokaufmann"**
**"Industriekaufmann"**
I'm using a decompound filter which works pretty good and results in a number of subwords - _and if I understand docFreq right, they should have the following docFrequ-Values_:
**"Büro" = 1**
**"Kaufmann" = 2**
**"Kauf" = 2**
**"Mann" = 2**
**"Industrie" = 1**
Thus, a "Büro" should have a higher score than "Kaufmann", because "Kaufmann" appears in more documents and is thus a more "generic" term.
But when I search with explain, it shows the following details for the term "Buro":
..."description": "weight( **title:buro** in 1) [PerFieldSimilarity], result of:",...
`
```
{
"value": 0.18232156,
"description": "idf, computed as log(1 + (docCount - docFreq + 0.5) / (docFreq + 0.5)) from:",
"details": [
{
"value": 2,
"description": "docFreq",
"details": []
},
{
"value": 2,
"description": "docCount",
"details": []
}
]
},
```
`
docFreq is 2 instead of 1.
It does this for every subword - it's always docFreq = docCount.
Thus, when I search for "Bürokaufmann" I'm getting the same score for the title "Bürokaufmann" as for the title "Industriekaufmann"... basically I'm getting the same score for everything.
Could my mapping / index settings contain sth. weird that produces this error, or am I simply misunderstanding the meaning of docFreq?
Please note, that I am using only 1 Shard, so the "counts are calculated per shard"-thing is hopefully not my problem(?)
I'm thankfull for any suggestions and tipps!
---
### Author:  [@fsommer](https://discuss.elastic.co/u/fsommer)
#### Post date: [June 17, 2019, 3:54pm UTC](https://discuss.elastic.co/t/value-of-docfreq-is-wrong-using-single-shard/185846/2 "2019-06-17T15:54:11Z")
Okay, I think I found out what is happening:
The docFreq is calculated not per subword, but as sum of the docFreqs for all subwords.
Example:
Compoundword made of three Words A, B and C: "ABC"
Indexed document titles:
"A..."
"B..."
"C..."
Search for compound word "ABC" and the explanation will look like: "(A in title)... docFreq=3"
But search only for the single word "A" and it will be: "(A in title)... docFrequ=1"
The docFreq of a single word is correct, but if you search for the compound-word "ABC" the docFreq for a single subword will be the sum of the docFreq for A, B and C.
This becomes clearer in the explain text of new ES version 7, we are still using 5.
I still don't understand, why this is happening though.
We are using a multi\_match of type "cross\_fields" - maybe that's the problem.
---
### Author:  [@system](https://discuss.elastic.co/u/system)
#### Post date: [July 15, 2019, 3:54pm UTC](https://discuss.elastic.co/t/value-of-docfreq-is-wrong-using-single-shard/185846/3 "2019-07-15T15:54:19Z")
This topic was automatically closed 28 days after the last reply. New replies are no longer allowed.