Michael R Durbin wrote:

> To meet the searching needs of a new collection in our digital
> library, I was required to provide facet values to help refine
> search results.  Since we were using SRU as a middle layer
> between our repository and various collection-specific web
> applications, and this functionality seemed generally useful, the
> idea to create an SRU extension seemed appropriate....
>
> A description of the extension with an example response is online
> on our wiki:
>
>   http://wiki.dlib.indiana.edu/confluence/display/INF/Faceted+Search
>
> Thanks for any feedback you can offer.


I find your extension quite interesting, for many reasons.  ;-)

The only suggestion I have is in regards to request syntax. Instead  
of making the maxValueCount and offset be optional:

   (facetName[,maxValueCount][,offset])...

I suggest they be required:

   (facetName,maxValueCount,offset)...

By making maxValueCount and offset required values, delimited by some  
character, it should be easier to parse the request -- it will be  
trivial to dump the request into an array and check its validity and  
sanity. Finally, just because the values are required does not mean  
they can't equal null. This will accommodate for all values or server  
choice, as your documentation alludes to.

Kudos, and good luck. 'Sounds like a great void to fill.

-- 
Eric Lease Morgan
Head, Digital Access and Information Architecture Department
University Libraries of Notre Dame

(574) 631-8604