TOP and SCORE

[Doug Tody]

Hi Arnold -

I am not sure where you got this from: the mention of "score" in connection
with SIA referred to this as a service capability not as a parameter
(along with logical names, compression, etc.).  The query parameter
proposed in both cases is TOP.  TOP=N returns the top scoring N records.
To have a query parameter SCORE could also be useful but this would only
work if the score were normalized in some fashion.  In all the discussions
we have had of the SCORE heuristic the consensus has always been that
we don't want to try to normalize the score, mainly because the scoring
heuristic used is not defined except in general terms (intentionally, to
allow smart heuristics to be developed), and would vary from one service
implementation to the next, making it difficult to compare score values.

 	- Doug



On Tue, 26 Jul 2005, Arnold Rots wrote:

> Doug,
>
> I noticed in your presentation at the NVO team meeting that there are
> two query parameters that overlap between SIAP and SSAP: SCORE and TOP.
> They represent the same concept; to amke it worse, "TOP" is an allowed
> value of SCORE.  I think that is confusing and undesirable.
>
> I would suggest that TOP be dropped and SCORE be used in both cases.
> If it is considered important to allow a service to return a number of
> records other than 1 or ALL, one might consider allowing an integer
> value for SCORE (as for TOP), in addition to "ALL" and "TOP".
>
> Cheers,
>
>   - Arnold
>
> --------------------------------------------------------------------------
> Arnold H. Rots                                Chandra X-ray Science Center
> Smithsonian Astrophysical Observatory                tel:  +1 617 496 7701
> 60 Garden Street, MS 67                              fax:  +1 617 495 7356
> Cambridge, MA 02138                             arots at head.cfa.harvard.edu
> USA                                     http://hea-www.harvard.edu/~arots/
> --------------------------------------------------------------------------
>
>