how is calculated score in group queries?

[Vincenzo D'Amore <v....@gmail.com>]

Hi all,

I have a couple of questions about grouping, I hope you can help me.

I'm trying to understand how is calculated group score in group queries.

So, I did my home work and it seems that group score is taken from score of
first document for each group found, i.e.:

<lst name="grouped">
   <lst name="slug_preferenziale">
      <int name="matches">3653</int>
        <arr name="groups">
          <lst>
             <str name="groupValue">
                       /xxxxxx/yyyyyyy/xxxxxxxx
             </str>
             <result name="doclist" numFound="437" start="0"
maxScore="0.775318">
                <doc>
                   <str name="namesearch">
                        Document title
                   </str>
                        <float name="score">0.775318</float>
                 </doc>
[omissis]

So for all the groups, what I see is that maxScore is the same value of
first document into the returned group. Am'I right?

I'm still using Solr 4.8.1, any chance this thing is changed/fixed in the
early releases?

I as this because reading the documentation I see now we should prefer
"Collapse and Expand", even if not in all cases we can use it... not clear
when.

So what's the difference? Can be explained with a real word example?

Best regards and thanks for all the time you will spent with me,
Vincenzo


-- 
Vincenzo D'Amore
email: v.damore@gmail.com
skype: free.dev
mobile: +39 349 8513251

Re: how is calculated score in group queries?

[Erick Erickson <er...@gmail.com>]

bq: I'm still using Solr 4.8.1, any chance this thing is changed/fixed in the
early releases?

What do you want it changed to? IIUC this is the intended behavior.

As for the rest, I'll defer to others.

Best,
Erick

On Tue, Oct 25, 2016 at 2:19 AM, Vincenzo D'Amore <v....@gmail.com> wrote:
> Hi all,
>
> I have a couple of questions about grouping, I hope you can help me.
>
> I'm trying to understand how is calculated group score in group queries.
>
> So, I did my home work and it seems that group score is taken from score of
> first document for each group found, i.e.:
>
> <lst name="grouped">
>    <lst name="slug_preferenziale">
>       <int name="matches">3653</int>
>         <arr name="groups">
>           <lst>
>              <str name="groupValue">
>                        /xxxxxx/yyyyyyy/xxxxxxxx
>              </str>
>              <result name="doclist" numFound="437" start="0"
> maxScore="0.775318">
>                 <doc>
>                    <str name="namesearch">
>                         Document title
>                    </str>
>                         <float name="score">0.775318</float>
>                  </doc>
> [omissis]
>
> So for all the groups, what I see is that maxScore is the same value of
> first document into the returned group. Am'I right?
>
> I'm still using Solr 4.8.1, any chance this thing is changed/fixed in the
> early releases?
>
> I as this because reading the documentation I see now we should prefer
> "Collapse and Expand", even if not in all cases we can use it... not clear
> when.
>
> So what's the difference? Can be explained with a real word example?
>
> Best regards and thanks for all the time you will spent with me,
> Vincenzo
>
>
> --
> Vincenzo D'Amore
> email: v.damore@gmail.com
> skype: free.dev
> mobile: +39 349 8513251