# Modification of term weight **URL:** \ **Category:** Elasticsearch\ **Created:** [September 9, 2010, 10:57pm UTC](https://discuss.elastic.co/t/modification-of-term-weight/3318 "2010-09-09T22:57:15Z")\ **Posts on this page:** 1\ **Showing post:** 6
**Author:** ![kimchy](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/kimchy/32/44952_2.png) [@kimchy](https://discuss.elastic.co/u/kimchy)\ **Post date:** [September 10, 2010, 2:12pm UTC](https://discuss.elastic.co/t/modification-of-term-weight/3318/6 "2010-09-10T14:12:55Z")
Yea, I agree. Though its tricky to expose this functionality nicely... . Basically, on the indexing side, there is a possibility to control the weighting of a term for example by adding a payload to it that represent the score. And then, when searching, using a custom query that takes those payloads and adds them to the scoring. This means that when indexing, you will need to provide the weighting (or just the special ones), for example: "the women^2 went to the beach". This does mean that for each document you want to change the term weights, it will need to be indexed with a new value(s), for example: "the women^1.5 went to the beach^2". That format (^) denoting custom weight is something I invented here for the example. Then, when searching, those weights will be taken into account using a special custom\_weight query that will be created for it. Does that sound like something that will help you? On Fri, Sep 10, 2010 at 5:00 PM, Mykhailo Korbakov [rmihael@gmail.com](mailto:rmihael@gmail.com)wrote: > Oh I wish that this weird trick would be _my_ wish 🙂 > I can come up with solution for few of these corrected weights, but > unfortunately there's a plan for thousands of them. > > Don't you think that term weight access (both TF and IDF parts) can be > useful in ES? Having some way to modify IDF weights is really useful for > advanced ranking algorithms with implicit feedback processing. As for now we > have to pass terms weights specified in queries and it doesn't very > convenient. > > May be it is worth to open an issue in GitHub? > > On Fri, Sep 10, 2010 at 4:42 PM, Shay Banon [shay.banon@elasticsearch.com](mailto:shay.banon@elasticsearch.com)wrote: > > > No, you can't do that. But you can control it on the search aspect, by > > constructing a boosted query and filtered by specific docs. This solution > > really depends on the number of custom weights you wish to set though... . > > > > On Fri, Sep 10, 2010 at 4:39 PM, Mykhailo Korbakov [rmihael@gmail.com](mailto:rmihael@gmail.com)wrote: > > > > > Unfortunately it's not my case. > > > > > > My goal is to make changes like this: "set weight of term 'woman' in > > > document with id 1231231231 to 1.5". I don't think that it's possible with > > > custom\_score, or at least I'm missing something important about it. > > > > > > On Fri, Sep 10, 2010 at 4:21 PM, Shay Banon \< > > > [shay.banon@elasticsearch.com](mailto:shay.banon@elasticsearch.com)\> wrote: > > > > > > > It really depends on what exactly you are after, but custom\_score query > > > > might help here: > > > > [http://www.elasticsearch.com/docs/elasticsearch/rest\_api/query\_dsl/custom\_score\_query/](http://www.elasticsearch.com/docs/elasticsearch/rest_api/query_dsl/custom_score_query/) > > > > . > > > > > > > > On Fri, Sep 10, 2010 at 1:57 AM, rmihael [rmihael@gmail.com](mailto:rmihael@gmail.com) wrote: > > > > > > > > > Hi everybody. > > > > > > > > > > Is there any way to change term weight in the context of one > > > > > particular document? Or, other words, to change TF value of specific > > > > > term for specific document? > > > > > I need this trick to promote specific documents in the context of > > > > > predefined queries. May be there's some better way to achieve it? I > > > > > just can think any other then TF manipulation. > > > > > > > > > > Thank you in advance, > > > > > > > > > > -- Michael Korbakov --- _[View the full topic](https://discuss.elastic.co/t/modification-of-term-weight/3318)._