lucene-java-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Andrzej Bialecki>
Subject Re: Wikia search goes live today
Date Tue, 08 Jan 2008 22:24:01 GMT
Ryan McKinley wrote:
> Andrzej Bialecki wrote:
>> Lukas Vlcek wrote:
>>> So staring will be accommodated only during indexing phase. Does it 
>>> mean it
>>> will be pretty static value not a dynamically changing variable... 
>>> correct?
>>> In other words if I add my starts to some document it won't affect the
>>> scoring immediately but after indexing cycle. Correct?
>> (I'm not involved in Wikia development). There are some ways to go 
>> about it even in the pure Lucene-land, so that the updates are fast 
>> without reindexing the main content. Hint: ParallelReader.
> in solr (1.3-dev) you can have an external value source with a function 
> query...

True, although function query tends to bring more overhead ...

While we're on the subject of complex scoring - I read an interesting 
paper (I don't have a link now), which discussed a so called bucketed 
scoring. The idea is that if your basic scoring is good enough to ensure 
that top-N results are highly relevant, then you can split these results 
into buckets of k documents (let's say 10 ;) ), and within each bucket 
apply arbitrary re-ranking function, which is then very inexpensive to 
perform because of the limited number of documents.

Example: you have a large corpus of web pages, and you want home pages 
to appear first, even if they score somewhat lower - and it doesn't pay 
off to modify the base scoring, because of overfitting, i.e. the scoring 
would be good for home pages but poor for other relevant documents.

Best regards,
Andrzej Bialecki     <><
  ___. ___ ___ ___ _ _   __________________________________
[__ || __|__/|__||\/|  Information Retrieval, Semantic Web
___|||__||  \|  ||  |  Embedded Unix, System Integration  Contact: info at sigram dot com

To unsubscribe, e-mail:
For additional commands, e-mail:

View raw message