<div dir="ltr"><div><div><div>Yes, you need an observatory-specific model to calculate a score.<br></div><div>By its very nature, therefore, it will only be a relative score.<br></div><div>Example:<br></div>For Chandra we implemented a score that is based on instrument, exposure time, and off-axis angle<br></div>(PSF degrades with increasing off-axis angle).<br><br></div> - Arnold<br></div><div class="gmail_extra"><br clear="all"><div><div class="gmail_signature"><div dir="ltr">-------------------------------------------------------------------------------------------------------------<br>Arnold H. Rots Chandra X-ray Science Center<br>Smithsonian Astrophysical Observatory tel: +1 617 496 7701<br>60 Garden Street, MS 67 fax: +1 617 495 7356<br>Cambridge, MA 02138 <a href="mailto:arots@cfa.harvard.edu" target="_blank">arots@cfa.harvard.edu</a><br>USA <a href="http://hea-www.harvard.edu/~arots/" target="_blank">http://hea-www.harvard.edu/~arots/</a><br>--------------------------------------------------------------------------------------------------------------<br><br></div></div></div>
<br><div class="gmail_quote">On Mon, Apr 27, 2015 at 3:25 AM, Markus Demleitner <span dir="ltr"><<a href="mailto:msdemlei@ari.uni-heidelberg.de" target="_blank">msdemlei@ari.uni-heidelberg.de</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Hi Petr, hi SSA crowd,<br>
<span class=""><br>
On Sat, Apr 25, 2015 at 01:38:26AM +0200, Petr Skoda wrote:<br>
><br>
> And does anybody implemented TOP in scoring manner in SSAP ?<br>
<br>
</span>Well, DaCHS accepts TOP but treats it equivalently to MAXREC so far<br>
(which I claim is legal, as that simply means I give all matching<br>
results the same score).<br>
<br>
The basic difficulty in doing a meaningful implementation is that you<br>
need to compute a score, and this kind of scoring in general is<br>
either difficult (because to do it properly you need a statistical<br>
model of both the data and the user) or haphazard (involving<br>
combining more or less ad-hoc measures for how good a match is for a<br>
certain constraint weighted... somehow).<br>
<br>
I think it would be a moderately worthwhile effort to create a model<br>
of either kind for SSAP's parameter set and validate it with user<br>
studies. Has anyone perhaps already started on such a thing?<br>
<br>
My suspicion is that this model could work well across a multitude of<br>
services and domains with no or just a single parameter. Be that as<br>
it may, I'm afraid I don't see GAVO tackling something like that any<br>
time soon.<br>
<br>
Cheers,<br>
<br>
Markus<br>
<br>
</blockquote></div><br></div>