RE: Multiple languages, boosting and, stemming and KeywordRepeat

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RE: Multiple languages, boosting and, stemming and KeywordRepeat

Markus Jelsma-2
Hello,

And sorry to disturb again. Does anyone of you have any meaningful opinion on this peculiar matter? The RemoveDuplicates filter exists for a reason, but with query-time KeywordRepeat filter it causes trouble in some cases. Is it normal for the clauses to be absent in the debug output, but the boost doubled in value?

I like this behaviour, but is it a side effect that is considered a bug in later versions? And where is the documentation in this. I cannot find anything in the Lucene or Solr Javadocs, or the reference manual.

Many thanks, again,
Markus

 
 
-----Original message-----

> From:Markus Jelsma <[hidden email]>
> Sent: Wednesday 9th May 2018 17:39
> To: solr-user <[hidden email]>
> Subject: Multiple languages, boosting and, stemming and KeywordRepeat
>
> Hello,
>
> First, apologies for the weird subject line.
>
> We index many languages and search over all those languages at once, but boost the language of the user's preference. To differentiate between stemmed tokens and unstemmed tokens we use KeywordRepeat and RemoveDuplicates, this works very well.
>
> However, we just stumbled over the following example, q=australia is not stemmed in English, but its suffix is removed by the Romanian stemmer, causing the Romanian results to be returned on top of English results, despite language boosting.
>
> This is because the Romanian part of the query consists of the stemmed and unstemmed version of the word, but the English part of the query is just one clause per field (title, content etc). Thus the Romanian results score roughtly twice that of English results.
>
> Now, this is of course really obvious, but the 'solution' is not. To work around the problem i removed the RemoveDuplicates filter so i get two clauses for English as well, really ugly but it works. What i don't understand is the debug output, it doesn't list two identical clauses, instead, it doubled the boost on the field, so instead of:
>
>     27.048403 = PayloadSpanQuery, product of:
>       27.048403 = weight(title_en:australia in 15850) [SchemaSimilarity], result of:
>         27.048403 = score(doc=15850,freq=4.0 = phraseFreq=4.0
> ), product of:
>           7.4 = boost
>           3.084852 = idf(docFreq=14539, docCount=317894)
>           1.1848832 = tfNorm, computed as (freq * (k1 + 1)) / (freq + k1 * (1 - b + b * fieldLength / avgFieldLength)) from:
>             4.0 = phraseFreq=4.0
>             0.3 = parameter k1
>             0.5 = parameter b
>             15.08689 = avgFieldLength
>             24.0 = fieldLength
>       1.0 = AveragePayloadFunction.docScore()
>
> I now get
>
>     54.096806 = PayloadSpanQuery, product of:
>       54.096806 = weight(title_en:australia in 15850) [SchemaSimilarity], result of:
>         54.096806 = score(doc=15850,freq=4.0 = phraseFreq=4.0
> ), product of:
>           14.8 = boost
>           3.084852 = idf(docFreq=14539, docCount=317894)
>           1.1848832 = tfNorm, computed as (freq * (k1 + 1)) / (freq + k1 * (1 - b + b * fieldLength / avgFieldLength)) from:
>             4.0 = phraseFreq=4.0
>             0.3 = parameter k1
>             0.5 = parameter b
>             15.08689 = avgFieldLength
>             24.0 = fieldLength
>       1.0 = AveragePayloadFunction.docScore()
>
> So instead of expecting two clauses in the debug, i get one but with a doubled boost.
>
> The question is, is this supposed to be like this?
>
> Also, are there any real solutions to this problem? Removing the RemoveDuplicats filter looks really silly.
>
> Many thanks!
> Markus
>
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Re: Multiple languages, boosting and, stemming and KeywordRepeat

Alessandro Benedetti
Hi Markus,
can you show all the query parameters used when submitting the request to
the request handler ?
Can you also include the parsed query  ( in the debug)

I am curious to investigate this case.

Cheers

--------------------------
Alessandro Benedetti
Search Consultant, R&D Software Engineer, Director
www.sease.io

On Thu, May 17, 2018 at 10:53 PM, Markus Jelsma <[hidden email]>
wrote:

> Hello,
>
> And sorry to disturb again. Does anyone of you have any meaningful opinion
> on this peculiar matter? The RemoveDuplicates filter exists for a reason,
> but with query-time KeywordRepeat filter it causes trouble in some cases.
> Is it normal for the clauses to be absent in the debug output, but the
> boost doubled in value?
>
> I like this behaviour, but is it a side effect that is considered a bug in
> later versions? And where is the documentation in this. I cannot find
> anything in the Lucene or Solr Javadocs, or the reference manual.
>
> Many thanks, again,
> Markus
>
>
>
> -----Original message-----
> > From:Markus Jelsma <[hidden email]>
> > Sent: Wednesday 9th May 2018 17:39
> > To: solr-user <[hidden email]>
> > Subject: Multiple languages, boosting and, stemming and KeywordRepeat
> >
> > Hello,
> >
> > First, apologies for the weird subject line.
> >
> > We index many languages and search over all those languages at once, but
> boost the language of the user's preference. To differentiate between
> stemmed tokens and unstemmed tokens we use KeywordRepeat and
> RemoveDuplicates, this works very well.
> >
> > However, we just stumbled over the following example, q=australia is not
> stemmed in English, but its suffix is removed by the Romanian stemmer,
> causing the Romanian results to be returned on top of English results,
> despite language boosting.
> >
> > This is because the Romanian part of the query consists of the stemmed
> and unstemmed version of the word, but the English part of the query is
> just one clause per field (title, content etc). Thus the Romanian results
> score roughtly twice that of English results.
> >
> > Now, this is of course really obvious, but the 'solution' is not. To
> work around the problem i removed the RemoveDuplicates filter so i get two
> clauses for English as well, really ugly but it works. What i don't
> understand is the debug output, it doesn't list two identical clauses,
> instead, it doubled the boost on the field, so instead of:
> >
> >     27.048403 = PayloadSpanQuery, product of:
> >       27.048403 = weight(title_en:australia in 15850)
> [SchemaSimilarity], result of:
> >         27.048403 = score(doc=15850,freq=4.0 = phraseFreq=4.0
> > ), product of:
> >           7.4 = boost
> >           3.084852 = idf(docFreq=14539, docCount=317894)
> >           1.1848832 = tfNorm, computed as (freq * (k1 + 1)) / (freq + k1
> * (1 - b + b * fieldLength / avgFieldLength)) from:
> >             4.0 = phraseFreq=4.0
> >             0.3 = parameter k1
> >             0.5 = parameter b
> >             15.08689 = avgFieldLength
> >             24.0 = fieldLength
> >       1.0 = AveragePayloadFunction.docScore()
> >
> > I now get
> >
> >     54.096806 = PayloadSpanQuery, product of:
> >       54.096806 = weight(title_en:australia in 15850)
> [SchemaSimilarity], result of:
> >         54.096806 = score(doc=15850,freq=4.0 = phraseFreq=4.0
> > ), product of:
> >           14.8 = boost
> >           3.084852 = idf(docFreq=14539, docCount=317894)
> >           1.1848832 = tfNorm, computed as (freq * (k1 + 1)) / (freq + k1
> * (1 - b + b * fieldLength / avgFieldLength)) from:
> >             4.0 = phraseFreq=4.0
> >             0.3 = parameter k1
> >             0.5 = parameter b
> >             15.08689 = avgFieldLength
> >             24.0 = fieldLength
> >       1.0 = AveragePayloadFunction.docScore()
> >
> > So instead of expecting two clauses in the debug, i get one but with a
> doubled boost.
> >
> > The question is, is this supposed to be like this?
> >
> > Also, are there any real solutions to this problem? Removing the
> RemoveDuplicats filter looks really silly.
> >
> > Many thanks!
> > Markus
> >
>
---------------
Alessandro Benedetti
Search Consultant, R&D Software Engineer, Director
Sease Ltd. - www.sease.io
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RE: Multiple languages, boosting and, stemming and KeywordRepeat

Markus Jelsma-2
In reply to this post by Markus Jelsma-2
Hi Alessandro,

I looked at the parsed_query again and spotted something that could be the problem. We extend ExtendedDismaxQParser for payload support among other things. I suspect something is going wrong with rewriting the claused of SynonymQuery there.

Thanks for letting me look at that part again, i clearly missed it the last time.

Thanks,
Markus
 
 
-----Original message-----

> From:Alessandro Benedetti <[hidden email]>
> Sent: Friday 18th May 2018 12:54
> To: [hidden email]
> Subject: Re: Multiple languages, boosting and, stemming and KeywordRepeat
>
> Hi Markus,
> can you show all the query parameters used when submitting the request to
> the request handler ?
> Can you also include the parsed query  ( in the debug)
>
> I am curious to investigate this case.
>
> Cheers
>
> --------------------------
> Alessandro Benedetti
> Search Consultant, R&D Software Engineer, Director
> www.sease.io
>
> On Thu, May 17, 2018 at 10:53 PM, Markus Jelsma <[hidden email]>
> wrote:
>
> > Hello,
> >
> > And sorry to disturb again. Does anyone of you have any meaningful opinion
> > on this peculiar matter? The RemoveDuplicates filter exists for a reason,
> > but with query-time KeywordRepeat filter it causes trouble in some cases.
> > Is it normal for the clauses to be absent in the debug output, but the
> > boost doubled in value?
> >
> > I like this behaviour, but is it a side effect that is considered a bug in
> > later versions? And where is the documentation in this. I cannot find
> > anything in the Lucene or Solr Javadocs, or the reference manual.
> >
> > Many thanks, again,
> > Markus
> >
> >
> >
> > -----Original message-----
> > > From:Markus Jelsma <[hidden email]>
> > > Sent: Wednesday 9th May 2018 17:39
> > > To: solr-user <[hidden email]>
> > > Subject: Multiple languages, boosting and, stemming and KeywordRepeat
> > >
> > > Hello,
> > >
> > > First, apologies for the weird subject line.
> > >
> > > We index many languages and search over all those languages at once, but
> > boost the language of the user's preference. To differentiate between
> > stemmed tokens and unstemmed tokens we use KeywordRepeat and
> > RemoveDuplicates, this works very well.
> > >
> > > However, we just stumbled over the following example, q=australia is not
> > stemmed in English, but its suffix is removed by the Romanian stemmer,
> > causing the Romanian results to be returned on top of English results,
> > despite language boosting.
> > >
> > > This is because the Romanian part of the query consists of the stemmed
> > and unstemmed version of the word, but the English part of the query is
> > just one clause per field (title, content etc). Thus the Romanian results
> > score roughtly twice that of English results.
> > >
> > > Now, this is of course really obvious, but the 'solution' is not. To
> > work around the problem i removed the RemoveDuplicates filter so i get two
> > clauses for English as well, really ugly but it works. What i don't
> > understand is the debug output, it doesn't list two identical clauses,
> > instead, it doubled the boost on the field, so instead of:
> > >
> > >     27.048403 = PayloadSpanQuery, product of:
> > >       27.048403 = weight(title_en:australia in 15850)
> > [SchemaSimilarity], result of:
> > >         27.048403 = score(doc=15850,freq=4.0 = phraseFreq=4.0
> > > ), product of:
> > >           7.4 = boost
> > >           3.084852 = idf(docFreq=14539, docCount=317894)
> > >           1.1848832 = tfNorm, computed as (freq * (k1 + 1)) / (freq + k1
> > * (1 - b + b * fieldLength / avgFieldLength)) from:
> > >             4.0 = phraseFreq=4.0
> > >             0.3 = parameter k1
> > >             0.5 = parameter b
> > >             15.08689 = avgFieldLength
> > >             24.0 = fieldLength
> > >       1.0 = AveragePayloadFunction.docScore()
> > >
> > > I now get
> > >
> > >     54.096806 = PayloadSpanQuery, product of:
> > >       54.096806 = weight(title_en:australia in 15850)
> > [SchemaSimilarity], result of:
> > >         54.096806 = score(doc=15850,freq=4.0 = phraseFreq=4.0
> > > ), product of:
> > >           14.8 = boost
> > >           3.084852 = idf(docFreq=14539, docCount=317894)
> > >           1.1848832 = tfNorm, computed as (freq * (k1 + 1)) / (freq + k1
> > * (1 - b + b * fieldLength / avgFieldLength)) from:
> > >             4.0 = phraseFreq=4.0
> > >             0.3 = parameter k1
> > >             0.5 = parameter b
> > >             15.08689 = avgFieldLength
> > >             24.0 = fieldLength
> > >       1.0 = AveragePayloadFunction.docScore()
> > >
> > > So instead of expecting two clauses in the debug, i get one but with a
> > doubled boost.
> > >
> > > The question is, is this supposed to be like this?
> > >
> > > Also, are there any real solutions to this problem? Removing the
> > RemoveDuplicats filter looks really silly.
> > >
> > > Many thanks!
> > > Markus
> > >
> >
>