TOP and SCORE

[Doug Tody]

The presentation referred to here (DAL update for the NVO team meeting)
is online at

http://chart.stsci.edu/twiki/pub/Main/TeamMeetingSummer2005/dal-update.pdf

if anyone is interested.  Items such as query parameter names have not yet
been updated to reflect the Kyoto discussions.

 	- Doug


On Tue, 26 Jul 2005, Doug Tody wrote:
> 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/
>> --------------------------------------------------------------------------
>> 
>> 
>
>