[Hibernate Seach] Show relevance

fabreax · **Posted:** Wed Jun 27, 2007 9:27 am

Hello,

It's me again.

Is it possible to show the relevance of a result ?

For example, I want to display :
First result, 90%
First result, 40%
First result, 5%

Thank you.

emmanuel · **Posted:** Fri Jun 29, 2007 10:56 am

First of all, I kind of thing it's a bad idea.
But definitively the application should have access to it.
John is working on it: http://opensource.atlassian.com/projects/hibernate/browse/HSEARCH-74

fabreax · **Posted:** Fri Jun 29, 2007 11:02 am

Ok thank you, and thank you John.

I want this value because I made a demo application, not for final users.

fabreax · **Posted:** Mon Jul 09, 2007 11:44 am

John is already on it ?

pudo · **Joined:** Fri Jul 06, 2007 5:45 pm **Posts:** 5

yeah, this would really be great to have ...

to push things even further: how about an API to push things into the ranking algorithm that add custom weighs at query-time? something like

Code:

public interface QueryScoreCallback {
      public float rate(Document document or Object o or whatever); 
}

but that's just a weird idea I wanted to post.

cheers, friedrich

emmanuel · **Posted:** Wed Jul 11, 2007 1:56 pm

For which use case?

pudo · **Joined:** Fri Jul 06, 2007 5:45 pm **Posts:** 5

a really obscure one, admittedly:

in my current project the physical distance between the user executing the query and a property of the retrieved document is a part of the hits relevance. also, certain other relationships between the user and the object can affect the score.

this is a pretty unusual requirement though, I guess, so I'll just go ahead and use the score projections once they become available.

cheers, friedrich

emmanuel · **Posted:** Wed Jul 11, 2007 2:29 pm

Lucene has something for that that we could expose potentially, but I need to look at their API

fabreax · **Posted:** Tue Jul 24, 2007 7:17 am

I see a getScore is now possible, but how ?

Only like that ? :

Code:

fullTextQuery.setIndexProjection(FullTextQuery.SCORE,FullTextQuery.THIS);
List results = fullTextQuery.list();
Object[] firstResult = (Object[]) results.get(0);
Float score = (Float) firstResult[0];       
System.out.println("score : "+firstResult[0]);

Moreover, if we want to normalize the score (in percent for example), is it possible to the get max Score ?
(http://jsourcery.com/api/apache/lucene/ ... pDocs.html)

emmanuel · **Posted:** Wed Jul 25, 2007 3:00 pm

yes that's how you can query it.

fabreax · **Posted:** Wed Jul 25, 2007 3:17 pm

Ok, thank you very much ;).

fabreax · **Posted:** Thu Aug 23, 2007 9:33 am

Is there a possibilité to get max score now ?

emmanuel · **Posted:** Tue Aug 28, 2007 2:58 pm

No I did some research, and it turns out that max score is not especially relevent, Hibernate returns a score between ]0 and 1], but the top score is not guaranteed to tbe 1.
Check here for more info discussions, http://opensource.atlassian.com/project ... SEARCH-101

fabreax · **Posted:** Wed Aug 29, 2007 3:30 am

Hum, I don't understand everything. Is there any possiblity to have the result scores sum equal to 1 ?

emmanuel · **Posted:** Thu Aug 30, 2007 5:13 pm

yes the formula used by Lucene to build score allows 1 (but not 0 which means that the object is irrelevant, hence excluded from the results :) )
So your results are included in ]0, 1]