Re: [htdig] Question about weighting

[Gilles D. <gr...@sc...>]

According to Malcolm Austen:
> On Thu, 21 Feb 2002, Gabriele Bartolini wrote:
> +     Sorry if this question may be silly, but I didn't know about this
> + before. I know I should have looked at the sources first, but I think that
> + users should perhaps know about this. Here is my question: by default,
> + ht://Dig gives different weights to words depending on the tag they are in.
> + What are the default weights?
> 
> I collected up various parts of the 3.1.5 documentation into a web page:
> 
>                http://wwwsearch.ox.ac.uk/scores.html
> 
> + header1 i:0 l:734   w:266
> + header2 i:0 l:800   w:200
> + header3 i:0 l:865   w:135
> 
> Those weights nicely show the undocumented (and unconfigurable)
> 'location' weight mentioned in my page above.

Back in July we discussed possible ways of configuring this, but none
of that ever made it into 3.1.6.  It occurred to me that we could have a
"location_factor" which would default to 1000, and words would be ranked
from that factor at the start of the document, down to 1 at the end,
multiplied by the appropriate scoring factor for the type of word in
question.  To make location irrelevant, you'd just set location_factor to
1 and all word scores would be multiplied by 1 regardless of location,
so only the other scoring factors would have any effect.  I think this
would be more intuitive and manageable than the last_word_factor we
discussed back in July, which wouldn't change the builtin factor of 1000
for first words.  Maybe you can nag me about this if/when Geoff and I
commit to a 3.1.7 release.

Meanwhile, I'll add a link to your web page in the FAQ.  Thanks.

-- 
Gilles R. Detillieux              E-mail: <gr...@sc...>
Spinal Cord Research Centre       WWW:    http://www.scrc.umanitoba.ca/~grdetil
Dept. Physiology, U. of Manitoba  Phone:  (204)789-3766
Winnipeg, MB  R3E 3J7  (Canada)   Fax:    (204)789-3930