Yep, it would be nice for MLT to have this feature, that's why I am
trying to do it from the querys before sending the query to Solr. These
are the steps I'm following:
1. execute a mlt.like() with the text document_example.getTitle()
against the field "Title" of all the other documents. This returns a
query containing the most relevant words in the example_document and in
the rest of documents in the Title. We will call this query
"QueryTitle". For example QueryTitle = (words^0.4 in^0.3 the^0.56
title^0.65)
2. execute a mlt.like() with the text document_example.getDescription()
against the field "Description" of all the other documents. This returns
a query containin the most relevant words in the example_document and in
the rest of documents in the Description. We will call this query
"QueryDescription". For example QueryDescription = (other^0.66 words^0.7
in^0.33 the^0.49 description^0.43)
Up to here, everything is possible with the options that offers MLT.
Now, with the info MLT gave me (QueryTitle and QueryDescription), i want
to look in Solr for the documents (and more filters) to retrieve the
best matches. But I want QueryTitle to be more important that
QueryDescription, for example 70% and 30% respectively. This means that
we should do QueryTitle^0.70 and QueryDescription^0.30. This means
having a query for Solr like this:
(words^0.4 in^0.3 the^0.56 title^0.65)^0.70 (other^0.66 words^0.7
in^0.33 the^0.49 description^0.43)^0.30
The question is...is Solr able to "understand" a query boosted who has
its terms boosted already? (Remember that MLT returns the "interesting
terms" boosted). This does make sense? Will the words obtained from a
mlt.like() on the title be 70% relevant while the words obtained from a
mlt.like() on the description will be only 30% relevant?
Of course it would be a nice feature to be able to boost these things
natively and do only one call to MLT...Don't hesitate to contact me if
you need any help on developing this feature.
Thanks!
Pako
Erik Hatcher wrote:
No, the MLT feature does not have that kind of field-specific boosting
capability. It sounds like it could be a useful enhancement though.
Of course you do get boosts for "interesting terms" already, but maybe
having an additional field-specific boost would be a nice touch too.
Erik
On Apr 22, 2008, at 9:13 AM, Francisco Sanmartin wrote:
I know that only one query of that type does not change anything. But
when it's two or more with different boosts, i hope it does. Here is
the situation:
My docs have "Title" and "Description". What I want to do is to give
more relevancy to the morelikethis on the title than on the
description. So the query would be like this:
query = (words^0.4 in^0.3 the^0.56 title^0.65)^0.70 (words^0.7
in^0.33 the^0.49 description^0.43)^0.30
This way, the words in the title are more relevant than the words in
the description, right?
Thanks!
Pako
Erik Hatcher wrote:
On Apr 21, 2008, at 5:02 PM, Francisco Sanmartin wrote:
Is it possible to boost the query that MoreLikeThis returns before
sending it to Solr? I mean, technically is possible, because you
can add a factor to the whole query but...does it make sense?
(Remember that MoreLikeThis can already boosts each term inside the
query).
For example, this could be a result of MoreLikeThis (with native
boosting enabled)
queryResultMLT = (this^0.4 is^0.5 a^0.6 query^0.33 of^0.29
morelikethis^0.67)
what I want to do is
queryResulltMLT = (this^0.4 is^0.5 a^0.6 query^0.33 of^0.29
morelikethis^0.67)^0.60 <---(notice the boost of 0.60 for the
whole query)
That last boost wouldn't change the doc ordering at all, so it'd be
kinda useless.
What are you trying to accomplish?
Erik
