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From Doug Cutting <cutt...@lucene.com>
Subject Re: field boosting best practise
Date Tue, 16 Dec 2003 18:03:20 GMT
If you wish to boost the title field for every query then it would be 
easiest to boost the title clause of your query, with Query.setBoost(). 
  Field.setBoost() should only be used when you want to give a field 
different boosts in different documents, but since you want to boost all 
titles by the same amount, you'll find it easier to boost at query time. 
  That way you can experiment with the boost amount without re-building 
the index.  The values of Field.setBoost() are built into the index and 
are harder to change.  Thus I recommend using Query.setBoost() instead. 
  Construct a query for each field to be searched (by hand, or with the 
QueryParser), boost each of these field queries separately, then build a 
BooleanQuery that combines these into a single Query that you then 
execute.  I hope that makes sense.

Doug

Maurice Coyle wrote:
> hi,
> i was wondering what's the best approach to take when boosting the value of
> a particular field.
> 
> i'm searching over a document's title, url and contents fields and i want to
> try giving certain fields a boost at times to see if it improves my results.
> so for instance if i want to give the title field more weight i can use
> Field.setBoost() to do this.
> 
> my question is, say for example i want to give the title field twice as much
> weight as the url and contents fields.  do i set the boost value of title to
> be 2.0 or should i set the boost value of the url and contents fields to be
> 0.25 and the boost value of the title field to be 0.5 (thereby having all
> boost values adding up to 1 so all the socres are normalised with respect to
> the title field's boost).
> 
> i just find the messages in the archives a little confusing regarding this,
> i can't see which approach is best, or if either is best.
> 
> any help appreciated.
> maurice
> 
> 
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