Xapian discuss - Apr 2007 - How to ignore many occurrence of the same term in one document for relevance computation?

Hello there,

I would like to ask how can I make Xapian to ignore relevance computation
for documents that has many time occurrence of the same term. Or differently
to say I would like to have Xapian ignore relevance computation based on how
many times terms is in document.


Search example term "Kevin"
  1. Document_A contains: Kevin Kevin Kevin Kevin (Relevance 100%)
  2. Document_B contains: Kevin (Relevance 100%)

I want both documents to have same relevancy. Is that possible?

-Kevin

On Thu, Apr 12, 2007 at 11:44:35AM -0700, Kevin Duraj wrote:
> I would like to ask how can I make Xapian to ignore relevance computation
> for documents that has many time occurrence of the same term. Or
differently
> to say I would like to have Xapian ignore relevance computation based on
how
> many times terms is in document.
You can do this by fiddling with the Weight mechanism. The key here is
to drop the wdf (within document frequency) of each term. I think you
can just set k1_ to 0 in BM25Weight, but I've never tried it.

Use Xapian::Enquire::set_weighting_scheme() to replace the default
weighting scheme (you can construct a BM25Weight object with the
relevant parameters to pass in to this).

J

-- 
/--------------------------------------------------------------------------\
  James Aylett                                                  xapian.org
  james@tartarus.org                               uncertaintydivision.org